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CAS No. : | 87-99-0 | MDL No. : | MFCD00064292 |
Formula : | C5H12O5 | Boiling Point : | - |
Linear Structure Formula : | - | InChI Key : | HEBKCHPVOIAQTA-NGQZWQHPSA-N |
M.W : | 152.15 | Pubchem ID : | 6912 |
Synonyms : |
Xylite;Adonitol;Adonite;D-Xylitol;Ribitol
|
Num. heavy atoms : | 10 |
Num. arom. heavy atoms : | 0 |
Fraction Csp3 : | 1.0 |
Num. rotatable bonds : | 4 |
Num. H-bond acceptors : | 5.0 |
Num. H-bond donors : | 5.0 |
Molar Refractivity : | 31.96 |
TPSA : | 101.15 Ų |
GI absorption : | Low |
BBB permeant : | No |
P-gp substrate : | No |
CYP1A2 inhibitor : | No |
CYP2C19 inhibitor : | No |
CYP2C9 inhibitor : | No |
CYP2D6 inhibitor : | No |
CYP3A4 inhibitor : | No |
Log Kp (skin permeation) : | -8.99 cm/s |
Log Po/w (iLOGP) : | 0.34 |
Log Po/w (XLOGP3) : | -2.48 |
Log Po/w (WLOGP) : | -2.95 |
Log Po/w (MLOGP) : | -2.33 |
Log Po/w (SILICOS-IT) : | -1.59 |
Consensus Log Po/w : | -1.8 |
Lipinski : | 0.0 |
Ghose : | None |
Veber : | 0.0 |
Egan : | 0.0 |
Muegge : | 2.0 |
Bioavailability Score : | 0.55 |
Log S (ESOL) : | 1.04 |
Solubility : | 1680.0 mg/ml ; 11.0 mol/l |
Class : | Highly soluble |
Log S (Ali) : | 0.9 |
Solubility : | 1200.0 mg/ml ; 7.91 mol/l |
Class : | Highly soluble |
Log S (SILICOS-IT) : | 2.06 |
Solubility : | 17300.0 mg/ml ; 114.0 mol/l |
Class : | Soluble |
PAINS : | 0.0 alert |
Brenk : | 0.0 alert |
Leadlikeness : | 1.0 |
Synthetic accessibility : | 2.94 |
Signal Word: | Warning | Class: | N/A |
Precautionary Statements: | P261-P305+P351+P338 | UN#: | N/A |
Hazard Statements: | H315-H319-H335 | Packing Group: | N/A |
GHS Pictogram: |
* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
100% | With hydrogen; In water; at 120℃; under 15001.5 Torr; for 0.166667h; | To 0.5 g of xylose in 40 ml of H20, HRO/Na-beta catalyst (50 mg) was added in a reactorvessel. The reactor vessel was then heated at 120 C for 10 mm under H2 pressure (20 bar).After completion of the reaction, the catalyst was separated by using centrifuge and theobtained clear product mixture was analyzed by UHPLC. The reaction gave 100% conversionof xylose with 100% yield of xylitol. |
88% | With sodium tetrahydroborate; In water; at 20℃; for 3h; | To a solution of d-xylose (1g) in water (10ml) was added an aqueous solution of sodium borohydride (0.2g/5ml H2O). The reaction mixture was kept at room temperature for 3h. When the reduction was complete the reaction mixture was acidified with a few drops of acetic acid, deionized with cation/anion ion-exchange resin and evaporated to dryness. Crystallization from ethanol afforded optically inactive d-xylitol (880mg; 88%). |
79% | With hydrotalcite; Pt/gamma-Al2O3; hydrogen; In water; at 60℃; under 12001.2 Torr; for 4h;Green chemistry;Catalytic behavior; | General procedure: Glucose and xylose hydrogenation reactions were carried out in a batch reactor (Amar equipments, India). The reactor was charged with 0.83 mmol of glucose or 1.00 mmol of xylose in 35 mL water. During reactions catalyst/substrate ratio was kept constant at 1:2 (wt/wt). When reactions were conducted using HT, 0.075 g of HT was added. Experiments were conducted at temperatures ranging between 60 C and 190 C under 8-24 bar of hydrogen pressure.The reactions were conducted for 2-6 h. Reaction mixture was analyzed using HPLC (Agilent, USA) equipped with HC-75 Pb++(9 m,7.8 mm × 300 mm) column. Water was used as an eluent, at the flow rate of 0.6 mL/min, and RID (model no. 1260 infinity) was used to detect the compounds. The products which are poorly separable by using HC-75 Pb++column, were analyzed using HPLC (Shimadzu,Japan) equipped with HC-75 H+(9 m, 7.8 mm × 305 mm) column. Succinic acid (0.5 mmol) is used as an eluent (0.5 mL/min). The refractive index detector (Model no. RID-6A) was used for the detection and calibration of compounds. The calibration of all the compounds was done using commercially available standards. |
In water; | Example 1 A vertically upright heat-insulated high-pressure tube made of stainless steel of internal diameter 45 mm and length 1 m was packed witht 1.4 l of a hydrogenation catalyst prepared by tableting a metal powder of an Ni/Zr alloy having a Zr content of 12.8%, which catalyst, at a cylinder height of 5 mm and a diameter of 5 mm, had a compressive strength of 109 N on the curved cylinder surface and an internal surface area of 74 m2 /g. 450 ml of a 45% strength solution of D-xylose in demineralized oxygen-free drinking water having a pH of 7.0 were continuously pumped per hour through this tube, ascending from bottom to top, together with five times the molar amount of high-purity hydrogen at a pressure of 300 bar. Aqueous solution and hydrogen were passed together beforehand through a heat exchanger and heated in such a manner that they entered the high-pressure tube at a temperature of 60 C. The mixture of aqueous solution and excess hydrogen leaving the high-pressure tube was passed via a cooler into a separator from where the hydrogen, after replacing the amount consumed, was pumped back into the preheater, together with fresh D-xylose solution and from there back into the high-pressure tube. The colorless and clear aqueous solution was depressurized and concentrated in a falling-film evaporator to a sugar alcohol content of approximately 75% and then crystallized after further evaporation in a vacuum crystallizer with cooling. A white, slightly hygroscopic, odorless solid product was obtained, which was processed to give a fine crystalline powder. The xylitol formed was otherwise highly pure and, in the stable rhombic crystal form, had a melting point of 94 C. The content of non-hydrogenated D-xylose was <0.1%. Ni and Zr contents were each ?1 ppm. The activity of the catalyst was unchanged even after a running time of 1852 hours. | |
With hydrogen; In water; at 120℃; under 41254.1 Torr; for 1h;Autoclave; Inert atmosphere; Green chemistry;Catalytic behavior; | The xylose hydrogenation experiments catalyzed by Ru/HYZwere carried out batch wise in 300 mL of three phase slurry reactorin the temperature range from 100 to 140 C at hydrogen pressure(2.0-5.5 MPa) by various stirring rate (400-1200 rpm). In typical hydrogenation experiment, required amount of catalyst (Ru/HYZ)and 100 mL of xylose solution were charged into stainless steel autoclave reactor. The reactor was fitted air tight and flushed with nitrogen gas three times at room temperature. Then, reactor was brought to desired temperature and pressurized with hydrogen which was considered as the zero reaction time. Hydrogenation reaction was initiated by stirring the entire reaction mass. Constant hydrogen pressure was maintained by supplying hydrogen gas manually through gas inlet valve during the reaction. During hydrogenation at different time intervals, the product components were analyzed using a HPLC (Younglin Instrument, Acme 9000)equipped with refractive index (RI) detector and Sugar-Pak column.De-ionized water was used as an eluent for the analysis at a flowrate of 0.4 mL/min at 70 C. After a stipulated period, the stirring was stopped and the reactor was abruptly cooled down, depressurized,flushed with N2, opened and decanted the reaction mixture from the catalyst to collect sample for final analysis. Xylose (XLS) conversion, selectivity to main xylitol (XTL) and arabitol (ARB) are calculated using following expressions. XLSConv. (%)=(1- mole of xylose at particular time/initial mole of xylose)×100 XTLSelc. (%)=(mole of XTL/mole of all products formed)×100 ARBSelc. (%)=(mole of ARB/mole of all products formed)×100 | |
With hydrogen; In water; at 120℃; under 41254.1 Torr; for 2h;Autoclave;Activation energy; Kinetics; | Hydrogenation experiments of xylose (20 wt.% in 200 ml of H2O)were carried out batch wise in 300 mL of three phase slurry reactorin the temperature range from 80 to 120 C at hydrogen pressure(40-65 bar) at constant stirring rate (1200 rpm). In a typical hydrogenationexperiment, required amount of catalyst Ru/PSN and 200 ml of xylosesolution were charged into stainless steel autoclave reactor. Thereactor was fitted air tight and flushed with nitrogen gas three times atroom temperature. Then, reactor was brought to desired temperatureand pressurized with hydrogen which was considered as the zero reactiontime. Hydrogenation reaction was initiated by stirring the entire reactionmass. During hydrogenation at different time intervals, theproduct components were analyzed using a HPLC (Younglin Instrument,Acme 9000) equipped with refractive index (RI) detector and Sugar-Pakcolumn [21]. | |
With hydrogen; In water; at 120℃; under 60006 Torr; for 6h; | Samples 10, 11, 14, 19 and 20 were evaluated for xylose hydrogenation in a batch reactor. Before reaction, the catalysts were reduced in-situ at 450 C. for 4 h with a heating ramp rate of 3 K/min. The test was conducted under 80 bar hydrogen pressure at 120 C. for 6 h. The catalyst loading was about 5 mL (about 5.1-5.5 g) in each test. The feed contained about 10 wt % xylose (food grade) aqueous solution with total about 100 mL in volume. The conversion efficiency and selectivity for xylitol was determined as follows: (0082) Conversion = mol . of xylose consumd mol . of xylose input × 100 % S xylitol = mol . of xylitol produced × 5 mol . of xylose consumed × 5 × 100 % (0083) The conversion and xylitol selectivity from xylose hydrogenation after 6 h is shown in Table 6. For all the catalyst materials, the conversion was high (above 98%), but the xylitol selectivity varied. NiCu catalyst material showed a higher selectivity compared to Ni catalyst material; for example, NiCu-ZrO2/MnOx (Sample 14) showed about 99.9% xylitol selectivity while Ni-ZrO2/MnOx (Sample 20) showed about 90.9% xylitol selectivity, where the catalysts were prepared based on the same carrier. The carbon selectivity to xylitol dropped significantly from 90.9% for Sample 20 to only 50% for Sample 19, both of which are Ni-ZrO2/MnOX materials but the later had a much higher Mn loading. For Sample 19, about 12% GYL selectivity, about 10% EG selectivity, and about 10% PG selectivity were observed in the final product, and the other carbon was possibly lost as coke and in gas. | |
Xylitol obtained was 175 g/l from 250 g/l of xylose at 98% of conversion. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With hydrogen;nickel; In methanol; ethanol; water; at 50℃; under 760.051 Torr;Product distribution / selectivity; | Example 3 :; Electrochemical decarboxylation of n L-gulonate salt to produce xylitol; [091] Sodium L-gulonate (2.67 g, . 01222 mol) was dissolved in 43 mL of methanol-water (46. 2% v/v). The solution was subjected to electrolysis in a undivided cell with a graphite anode at a constant 9.99 volts for 5.32 watt-hours. The electrolyte solution was then brought to 110 mL with ethanol-water (50%) and hydrogenated by the addition of Raney Nickel and the application of hydrogen gas at 1 atmosphere at 50C. The resulting hydrogenated syrup contained 0.87 g xylitol (47% of theoretical yield) and 1.10 g sodium L-gulonate (41% of the starting material on a molar basis). |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
60% | With dmap; triethylamine; In dichloromethane; at 20℃; for 16h;Cooling with ice; | 3 g of xylitol, 20 mL of triethylamine, 50 mg of dimethylaminopyridine were sequentially added to a 200 mL round bottom bottle.100 mL of dichloromethane was slowly added dropwise to 12 mL of acetic anhydride with stirring in an ice bath. After the addition is completed, the ice bath is removed, and the system is stirred at room temperature for 16 hours.Time. The reaction mixture was washed with water, aq. At lastThe product was obtained by column chromatography (petrole ether: ethyl acetate = 2:1) to afford product 1q. |
With pyridine; for 2h;Heating; | General procedure: Compounds (10 mg) was heated in an ampule along with 5 mL of aqueous 12% HCl at 90 for 2h. The aglycone was extracted with chloroform, and each aqueous residue was adjusted to pH 7.0 with12% NaOH and reduced with NaBH4 (40 mg), followed by acidification with dilute CH3COOH, andthen co-distilled with pure CH3OH to remove excess boric acid. The reduced sugars were acetylated with 1:1 pyridine-Ac2O in a boiling water bath for 2 h to give the alditol acetates, which were analyzedby GLC performed with a HP 6890 N gas chromatograph (Agilent, American) equipped with a flameionization detector. The instrument was fitted with a HP-5 capillary column (30 m × 0.32 mm × 0.25mm) by FID detector with N2 as carrier gas. The injector temperature was set at 250 and the columntemperature program was as follows: the initial temperature of 120 was increased by 38/min to thefinal temperature of 210 , then was held 4 min. The detector temperature was set at 300 . Thestandard monosaccharides were subjected to the same reaction and GC analysis under the sameconditions (D-galactose, tR, 25 min; D-xylose, tR, 19 min). |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With hydrogenchloride In methanol at 85℃; for 24h; |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With sulfuric acid In water at 160℃; for 2h; Yield given. Yields of byproduct given. Title compound not separated from byproducts; |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With hydrogen In water at 80℃; |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
98% | for 27h; Microbiological reaction; | |
With potassium phosphate buffer; Gluconobacter oxydans ATCC 621 membrane fraction; Gluconobacter oxydans phosphate buffer-soluble fraction at 30℃; for 40h; |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
Stage #1: XYLITOL; acetone With hydrogen cation Stage #2: 3‑(perfluoro‑n‑butyl)‑1,2‑epoxypropane With boron trifluoride diethyl etherate In di-isopropyl ether for 10h; Heating; |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With hydrogen;sponge type Raney nickel type catalyst; In water; at 110℃; under 37503.8 Torr; for 0 - 2.5h;Product distribution / selectivity; | Example 10; The effect of xylonic acid on the hydrogenation of xylose to xylitol; A xylose solution (50% xylose by weight) was prepared by dissolving xylose in ion -exchanged water. The xylose solution was hydrogenated at a temperature of 11O0C and at a hydrogenation pressure of 50 bar with a mixing <n="27"/>rate of 1800 rpm over sponge type Raney nickeltype catalyst (Activated Metals). The catalyst load was 5% by weight (dry substance content of 50%) of the initial xylose amount. The hydrogenation reactor was the same as in Example 1.Hydrogenations were performed for 120 to 150 minutes. In one hydrogenation test series, 0.5% by weight of xylonic acid (calculated on the total xylose solution) was added to the xylose solution before the start of each hydrogenation batch. A control test was performed without the addition of xylonic acid. Five consecutive hydrogenation batches were performed with the same catalyst without regeneration of the catalyst. The conversion of xylose to xylitol was monitored up to 150 minutes.The conversion results are shown in Figure 22. The results show that xylonic acid inevitably slows down the hydrogenation rate of xylose to xylitol compared to the tests without the addition of xylonic acid. The deactivation of the nickel catalyst from batch to batch was clear when xylonic acid was present. Furthermore, the addition of xylonic acid remarkably increased catalyst leaching. | |
With D-xylonic acid; hydrogen;sponge type Raney nickel type catalyst; In water; at 110℃; under 37503.8 Torr; for 0 - 2.5h;Product distribution / selectivity; | Example 10; The effect of xylonic acid on the hydrogenation of xylose to xylitol; A xylose solution (50% xylose by weight) was prepared by dissolving xylose in ion -exchanged water. The xylose solution was hydrogenated at a temperature of 11O0C and at a hydrogenation pressure of 50 bar with a mixing <n="27"/>rate of 1800 rpm over sponge type Raney nickeltype catalyst (Activated Metals). The catalyst load was 5% by weight (dry substance content of 50%) of the initial xylose amount. The hydrogenation reactor was the same as in Example 1.Hydrogenations were performed for 120 to 150 minutes. In one hydrogenation test series, 0.5% by weight of xylonic acid (calculated on the total xylose solution) was added to the xylose solution before the start of each hydrogenation batch. A control test was performed without the addition of xylonic acid. Five consecutive hydrogenation batches were performed with the same catalyst without regeneration of the catalyst. The conversion of xylose to xylitol was monitored up to 150 minutes.The conversion results are shown in Figure 22. The results show that xylonic acid inevitably slows down the hydrogenation rate of xylose to xylitol compared to the tests without the addition of xylonic acid. The deactivation of the nickel catalyst from batch to batch was clear when xylonic acid was present. Furthermore, the addition of xylonic acid remarkably increased catalyst leaching. | |
With palladium on activated charcoal; water; potassium hydroxide; silicon; at 170℃; for 3h;Inert atmosphere; Sealed tube; | 400Kg of potassium hydroxide and 1000Kg of water was added to the reactor and stirred at room temperature until there were no solid particles and obtained a solution A; [0056] (2) 800Kg glucose was added to the solution A obtained in step (1), stirring at room temperature until there were no solid particles, to obtain a solution B; [0057] (3) 100Kg of silicon was added to the solution B prepared in step (2), then Raney nickel 8Kg was added, and the reactor was sealed and replaced with nitrogen 3 times; [0058] (4) The reactor was heated to 130C, and the reaction was stirred for 5 hours, and the temperature was lowered to room temperature. Then it is filtered by a filter and filtrate C and residue D were obtained by filtration. The residue D is returned to the reactor in step (3) for recycling. The filtrate C is a Sugar alcohol silicon solution. [0059] (5)hydrochloric acid was added into the filtrate C, the pH was adjusted to 6 ~ 7, the temperature was raised to 60 C, and the reaction was stirred for 60 min. After filtration through a filter, the filtrate E and the solid F were obtained by filtration, and the solid F was dried to obtain white carbon. [0060] (6) The filtrate E was subjected to electrodialysis for salt removal to obtain a sorbitol solution G. The solution G was concentrated and spray-dried to obtain sorbitol. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
99.8% | With hydrogen;Ru(III) chloride, reduced with H2, inertated with N2, passivated with O2; In water; at 80 - 130℃; under 67506.8 Torr; | Eine Reaktionseinheit bestehend aus einem Hauptreaktor mit Umlauf sowie einem Nachreaktor wird mit dem UNTER I HERGESTELLTEN RUTHENIUMKATALYSATOR beschickt. Eine wssrige Lsung von Xylose (Quelle : Aldrich, Reinheit 99,6 %) mit einer Konzen- tration von 30 % wird unter Druck durch ein mit Silica-Strnglingen geflltes Rohr gefahren. Anschlieend wird diese Lsung in den Hauptreaktor, der eine Kopftempera- tur von 80 bis 130C aufwies, gefahren und danach durch den Nachreaktor, dessen Kopftemperatur an die Sumpftemperatur des Hauptreaktors angeglichen wurde, ge- fahren. Die Hydrierung erfolgte mit einem Druck von 90 bar. Das Verfahren liefert einen Umsatz von 99,8 % und eine Selektivitt bezogen auf Xylitol von 98,5 %. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With hydrogen;ruthenium chloride supported on zirconia (3 wtpercent of ruthenium) and calcined at 500 C (ruthenium dispersion 40percent; chlorine content 50 ppm); In water; at 60℃; under 36778.6 Torr; for 100h;Product distribution / selectivity; | EXAMPLE 6The procedure of example 4 was repeated except that the sugar containing 80 % xylose, 9 % arabinose, 5 % galactose, and 6 % glucose was used aes a reactant. After the reaction was conducted for 100 hours, the average purities of hydrogenated sugar alcohols were 79.8 %, 9.2 %, 5 %, and 5.9 % for xylitol, arabitol, galactitol, and sorbitol, respectively. Reactivity was not reduced even though the reaction was continuously performed for 1,000 hours or more. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With hydrogen;ruthenium chloride supported on silica (3 wtpercent of ruthenium) and calcined at 500 C (ruthenium dispersion 45percent; chlorine content 54 ppm); In water; at 50 - 60℃; under 36778.6 Torr; for 100h;Product distribution / selectivity; | EXAMPLE lRuthenium chloride was uniformly supported on silica pellets having a size of 2 mm so that a ruthenium content was 3 wt%, dried at 110C for 6 hours,. and calcined in a nitrogen atmosphere at 500C for 5 hours to produce a ruthenium catalyst having the ruthenium dispersion of 45 % and a chlorine content of 54 ppm. 2 g of catalyst thus produced was packed into a fixed-bed tubular reactor made of stainless steel, and reduction was subsequently conducted at 350C for 6 hours in the presence of hydrogen flowing at a rate of 50 cc per minute. After the reduction was completed, the flow rate of hydrogen was controlled so that it was 6 times the amount of xylose used, expressed aes a molar ratio. After a temperature and pressure of the reactor were set to 50C and 50 kg/cm2, a reactant was fed at a weight hourly space velocity (WHSV) of 0.18 h"1 (on the basis of xylose) to initiate a reaction. 40wt% solution of xylose dissolved in distilled water was used aes the reactant, and the product was analyzed using liquid chromatography provided with a refractive Index detector. After the reaction was carried out for 100 hours, the average conversion of xylose was 99.9 % and the selectivity of xylitol was 99.9 %. Reactivity was not reduced even though the reaction was continuously performed for 3,000 hours or more.EXAMPLE 2The procedure of example l was repeated except that the reaction temperature was 60C and the WHSV was 0.24 h"1. After the reaction was conducted for 100 hours, the average conversion of xylose was 99.9 % and the selectivity of xylitol was 99.8 %. Reactivity was not reduced even though the reaction was continuously performed for 1,000 hours or more. | |
With hydrogen;ruthenium chloride supported on alumina (3 wtpercent of ruthenium) and calcined at 500 C (ruthenium dispersion 3.0percent; chlorine content 54 ppm); In water; at 50℃; under 36778.6 Torr; for 10 - 48h;Product distribution / selectivity; | COMPARATIVE EXAMPLE 2The procedure of example l was repeated except that 3 wt% of ruthenium was dispersed with the ruthenium dispersion of 3.0 % in an alumina carrier, which had 85.3 % mesopores of 2 -50 nm and 14.7 % macropores of 50 - 10,000 nm based on a pore volume thereof, to produce a catalyst. After the reaction was conducted for 10 hours, the average conversion of xylose was 82.1 % and the selectivity of xylitol was 99.8 %. The catalyst was deactivated over time and the conversion of xylose was 72.1 % after 48 hours. | |
With hydrogen;ruthenium chloride supported on silica (3 wtpercent of ruthenium) and calcined at 500 C (ruthenium dispersion 2.8percent; chlorine content 54 ppm); In water; at 50℃; under 36778.6 Torr; for 100h;Product distribution / selectivity; | COMPARATIVE EXAMPLE lThe procedure of example l was repeated except that silica was used aes a carrier to produce 3 wt% of ruthenium catalyst having the ruthenium dispersion 2.8 %. After the reaction was conducted for 100 hours, the average conversion of xylose was 82.1 % and the selectivity of xylitol was 99.9 %. The production efficiency per time was reduced because the dispersion was low. |
With hydrogen;ruthenium chloride supported on silica (3 wtpercent of ruthenium) and calcined at 500 C (ruthenium dispersion >= 10percent; chlorine content 1000 ppm); In water; at 50℃; under 36778.6 Torr; for 20 - 270h;Product distribution / selectivity; | COMPARATIVE EXAMPLE 3The procedure of example l was repeated except that silica was used aes a carrier to produce a 3 wt% rutheniumcatalyst having the ruthenium dispersion of 10 % or more and a chlorine content of 1,000 ppm. After the reaction was conducted for 20 hours, the average conversion of xylose was 99.9 % and the selectivity of xylitol was 99.9 %. The catalyst was slowly deactivated over time and the conversion of xylose was 96.3 % after 270 hours. | |
With hydrogen;ruthenium chloride supported on silica/zirconia (90:10 wtpercent) (3 wtpercent of ruthenium) and calcined at 500 C (ruthenium dispersion 42percent; chlorine content 60 ppm); In water; at 60℃; under 36778.6 Torr; for 100h;Product distribution / selectivity; | EXAMPLE 7The procedure of example 4 was repeated except that silica-zirconia consisting of 90 wt% silica and 10 wt% zirconia was used aes a carrier to produce a 3 wt% ruthenium catalyst having the ruthenium dispersion of 42 % and a chlorine content of 60 ppm. After the reaction was conducted for 100 hours, the average conversion of xylose was 99.9 % and the selectivity of xylitol was 99.8 %. Reactivity was not reduced even though the reaction was continuously performed for 1,000 hours or more. | |
With hydrogen;ruthenium chloride supported on zirconia (3 wtpercent of ruthenium) and calcined at 500 C (ruthenium dispersion 40percent; chlorine content 50 ppm); In water; at 60℃; under 36778.6 Torr; for 100h;Product distribution / selectivity; | EXAMPLE 4Ruthenium Chloride was uniformly supported on zirconia pellets having a size of 3 mm, so that a ruthenium content was 3 wt%, dried at 110C for 6 hours, and calcined under a nitrogen atmosphere at 500C for 5 hours to produce a ruthenium catalyst having the ruthenium dispersion of 40 % and a chlorine content of 50 ppm. 6 g of catalyst thus produced were packed into a fixed-bed tubular reactor made of stainless steel, and the reduction was subsequently conducted at 350C for 6 hours in the presence of hydrogen flowing at a rate of 50 cc per minute. After the reduction was completed, the flow rate of hydrogen was controlled so that it was 6 times the amount of xylose used, expressed aes a molar ratio. After the temperature and pressure of the reactor were set to 60C and 50 kg/cm2, a reactant was fed at the WHSV of 0.10 h'1 (on the basis of xylose) to initiate a reaction. 40 wt% solution of xylose dissolved in distilled water was used aes the reactant, and the product was analyzed using liquid Chromatograph provided with a refractive Index detector. After the reaction was conducted for 100 hours, the average conversion of xylose was 99.9 % and the selectivity of xylitol was 99.8 %. Reactivity was not reduced even though the reaction was continuously performed for 1,000 hours or more. | |
With hydrogen;ruthenium chloride supported on zirconia (3 wtpercent of ruthenium) and calcined at 500 C (ruthenium dispersion >=10percent; chlorine content 1000 ppm); In water; at 60℃; under 36778.6 Torr; for 20 - 270h;Product distribution / selectivity; | EXAMPLE 4Ruthenium Chloride was uniformly supported on zirconia pellets having a size of 3 mm, so that a ruthenium content was 3 wt%, dried at 110C for 6 hours, and calcined under a nitrogen atmosphere at 500C for 5 hours to produce a ruthenium catalyst having the ruthenium dispersion of 40 % and a chlorine content of 50 ppm. 6 g of catalyst thus produced were packed into a fixed-bed tubular reactor made of stainless steel, and the reduction was subsequently conducted at 350C for 6 hours in the presence of hydrogen flowing at a rate of 50 cc per minute. After the reduction was completed, the flow rate of hydrogen was controlled so that it was 6 times the amount of xylose used, expressed aes a molar ratio. After the temperature and pressure of the reactor were set to 60C and 50 kg/cm2, a reactant was fed at the WHSV of 0.10 h'1 (on the basis of xylose) to initiate a reaction. 40 wt% solution of xylose dissolved in distilled water was used aes the reactant, and the product was analyzed using liquid Chromatograph provided with a refractive Index detector. After the reaction was conducted for 100 hours, the average conversion of xylose was 99.9 % and the selectivity of xylitol was 99.8 %. Reactivity was not reduced even though the reaction was continuously performed for 1,000 hours or more. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With hydrogen In methanol; ethanol; water at 50℃; | 1 Example 1:; Electrochemical decarboxylation of a D-glucuronate monohydrate salt to produce xylitol; [087] Sodium D-glucuronate monohydrate (2.69 g, 0.0115 mol) was dissolved in 43 mL of methanol-water (46.2% v/v). The solution was subjected to electrolysis in a undivided cell with a graphite anode at a constant 9.99 volts for 4.31 watt-hours. The electrolyte solution was then brought to 110 mL with ethanol-water (50%) and hydrogenated by the addition of Raney Nickel and the application of hydrogen gas at 1 atmosphere at 50°C. The resulting hydrogenated syrup contained 0.87 g xylitol (50% of theoretical yield) and 1.10 g soldium L-gulonate (42% of the starting material on a molar basis). [088] The theoretical yield, or"% of theoretical yield"was calculated as follows: First, the molecular weights were identified as follows: a. Sodium D-glucuronate monohydrate 235 b. Sodiutnmethylb-D-glucuronate 231 c. Sodiurn L-gulonate 219 d. Xylitol 152 [089] Next, the calculation was performed as follows : 2. 69 g of starting material is 0. 0114 mol and the theoretical yield of xylitol is 0.0114 X 152 or 1.74 g. The actual yield was 0.87 g, which is 50% of the theoretical yield. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
EXAMPLE 2 Reduction of L-xylonic acid to L-xylose and xylitol One molar (1 M) xylonic acid was reduced partly to xylose and xylitol by hydrogenating the acid using ruthenium catalyst as a catalyst. The conditions were: temperature 45 C., pressure 50 bar, reaction time 18 hours and the catalyst load 0.332 g of Ru/C (solids 49.4%) per 10 ml of 1 M xylonic acid solution. After the reaction the concentration of xylose was 0.2 g/100 ml, and of xylitol 14 g/100 ml. |
Yield | Reaction Conditions | Operation in experiment |
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95% | With toluene-4-sulfonic acid; In methanol; cyclohexane; water; | EXAMPLE 3 Preparation of Bis(4-fluoro-3-methylbenzylidene)xylitol A one liter four-necked cylindrical shaped reaction flask equipped with a Dean-Stark trap, condenser, thermometer, nitrogen inlet, and a mechanical stirrer was charged with 35.08 g of xylitol (0.2306 mole), 600 mL of cyclohexane, 63.70 g of <strong>[135427-08-6]4-fluoro-3-methylbenzaldehyde</strong> (0.4611 moles), 3.00 g of p-toluenesulfonic acid, 2.5 mL of water, and 210 mL of methanol. The reaction was stirred and heated under reflux with removal of water through the Dean Stark trap. The reaction becomes very thick and additional solvent is added as needed. After about six hours, the reaction is cooled, neutralized with potassium hydroxide, and filtered. The wet cake was washed thoroughly with water and cyclohexane, dried in a vacuum oven at 110 C. to give 69.46 g of Bis(4-fluoro-3-methylbenzylidene)xylitol (as determined through standard analyses). The purity was about 95% as determined by GC. The melting point was determined to be (DSCa20 C./min) about 222.9 C. |
Yield | Reaction Conditions | Operation in experiment |
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EXAMPLE 1 Method for Preparing Xylityl Glucoside 703.0 g of xylitol are introduced into a glass reactor equipped with a jacket through which circulates a heat transfer fluid, and equipped with an effective stirring device. The xylitol is melted at a temperature of 135 C., and the viscous paste thus obtained is cooled to 115 C. Glucose is then added gradually to the reaction medium so as to allow it to disperse homogeneously. An acid catalytic system consisting of 1.29 g of 96% sulfuric acid is added to the mixture thus obtained. The reaction medium is placed under a partial vacuum of 90 mbar to 45 mbar, and kept at a temperature of 100 C.-105 C. for a period of 4 h 30 min with evacuation of the water formed by means of a distillation assembly. The reaction medium is then cooled to 95 C.-100 C. and neutralized by adding 5 g of sodium hydroxide at 30%, so as to bring the pH of a solution containing 1% of this mixture to a value of 5.0. The characteristics of the mixture thus obtained are as follows: appearance (visual): orange wax at ambient temperature; pH solution at 1%: 5.0; residual xylitol: 55.8%; residual glucose: <1%. |
Yield | Reaction Conditions | Operation in experiment |
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92% | With sulfuric acid; In 1,4-dioxane; Trichloroethylene; | EXAMPLE 12 A powdery reaction mixture is obtained in the same manner as in Example 8 with the exception of using 24.0 g of xylitol, 41.5 g of p-chlorobenzaldehyde, 0.5 g of 50% sulfuric acid, 60 ml of trichloroethylene and 18 ml of dioxane. The mixture is similarly after-treated, affording di-(p-chlorobenzylidene)xylitol in a yield of 92% with a purity of 97%. |
Yield | Reaction Conditions | Operation in experiment |
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L-p-Boronophenylalanine-polyol or -aminopolyol complexes are prepared by combining 0.5 mM of alpha-deuterated or alpha-hydrogenated L-p-BPA with between 1.00 and 1.05 equivalents of complexing agent (with the exception of poorly complexing polyols and carbohydrates, in which up to 4.3 equivalents of polyol or carbohydrates are used) in 2 mL of water. One equivalent of NaOH (1 mL of 0.5 M) is then added and the slurry gently warmed if needed in order to dissolve all solids. The pH is then monitored and reduced to between 7.5 and 7.3 by the addition of Dowex50WX4-50 ion exchange resin. The clear solution is then passed through a 0.2 mum syringe filter and then freeze-dried to constant weight. 1H and 13C NMR spectra are recorded on a GE 300 MHz FT-NMR spectrometer with D2O buffered at 7.4 [Bates, R G, Bower, V E. 1956. Alkaline solutions for pH control. Anal. Chem. 28:1322-1324] as the solvent. The binding constants are calculated at three different concentrations by integration of the free L-p-BPA aromatic protons (7.73 and 7.33 ppm) compared with those of the L-p-BPA complexes (7.5 and 7.2 ppm). Spectra of the 1:1 complexes are reported. L-p-boronophenylalanine-xylitol complex 1H NMR delta 7.52 (d, J=7.3 Hz, 2H), 7.20 (d, J=7.3 Hz, 2H), 3.95 (dd, J=8.1, 5.1 Hz, 1H), 3.25 and 3.02 (ABq, JAB=14.7 Hz, the peaks at 3.25 and 3.02 are further split into d with J=5.1 and 8.1, respectively, 2H); 13C NMR delta 177.0 (s), 146.0 (s), 135.8 (s), 135.1 (d, 2C), 130.9 (d, 2C), 77.8 (d), 74.6 (d), 73.4 (d), 66.0 (t), 65.3 (t), 58.8 (d), 39.0 (t). |
Yield | Reaction Conditions | Operation in experiment |
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Example 7Synthesis of PGME Enriched Polyol Esters of Soy OilThis Example sets forth a representative synthesis of a propylene glycol monoester from a vegetable oil and the hydrogenolysis product mixture from the hydrogenolysis of sorbitol.Sorbitol was subjected to hydrogenolysis substantially as set forth in Example 1. The hydrogenolysis product was then subjected to distillation to remove the water. The compositions of the hydrogenolysis product before and after stripping are set forth in Table 7. TABLE 7 Composition of Hydrogenolysis Product Hydrogenolysis product Hydrogenolysis product Compound before stripping (wt %) after stripping (wt %) Sorbitol 6.2% 10.0% Xylitol 2.2% 3.5% Erthyritol 0.8% 1.3% Lactate 1.0% 1.6% Glycerol 10.9% 17.6% <strong>[3068-00-6]1,2,4-Butanetriol</strong> 0.5% 0.8% Ethylene glycol 11.4% 18.4% Propylene glycol 22.3% 36.0% 2,3-Butanediol 1.4% 2.3% 1,3-Butanediol 1.0% 1.6% 1,2-Butanediol 2.5% 4.0% Ethanol 0.4% 0.6% Isopropanol 0.2% 0.3% Water 38.0% 0% Unknown 1.2% 1.9% A 1 liter autoclave reactor was charged with RBD soybean oil (refined, bleached, and deodorized soybean oil, 160 g), the hydrogenolysis product mixture from sorbitol (165 g), potassium acetate (0.08 g), and lithium hydroxide (0.02 g). The reactor headspace was purged with nitrogen. The reactor was pressurized with nitrogen at 350 psi and agitation at 800 rpm was began. The reaction mixture was heated to 240 C. over 1 hour at which time the pressure has increased to 550 psi. The reaction was held at 240 C. for 1.5 hours and then rapidly cooled to room temperature. The contents of the reactor were placed in a separatory funnel and neutralized with 0.5 g of conc. H3PO4, The mixture was extracted with hexanes and the organic layer was washed once with four times its volume of deionized water. The organic layer was dried over anhydrous magnesium sulfate and filtered. The filtrate was concentrated with a rotary evaporator under reduced pressure to give a product having a Lovibond color of 2.9R., 14.0Y. The product composition was 60-81% propylene glycol monoester and 5% propylene glycol diester with an acid value of 21.6. This material may be used as a 100% biobased polyol ester replacement for petroleum derived PGMEs, for example as a coalescent in a latex paint formulation. |
Yield | Reaction Conditions | Operation in experiment |
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Example 8Candle Wax EstersThis Example sets forth a representative synthesis of a waxy propylene glycol monoester from a hydrogenated vegetable oil and the hydrogenolysis product mixture.A 1 L three neck round bottom flask was fitted with a heating mantle, a magnetic stirrer, a reflux condenser, and nitrogen sparge. Sorbitol was subjected to hydrogenolysis to obtain a hydrogenolysis product containing polyols (before stripping) and a composition as recited in Table 7, then heated under vacuum in a rotary evaporator to remove water and lower molecular weight alkyl monohydroxyl alcohols to obtain a stripped mixed polyol sorbitol hydrogenolysis product mixture (Table 7). The reaction vessel was charged with melted soy titer (fully hydrogenated soybean oil, 150 g) and the stripped mixed polyol mixture from the hydrogenolysis of sorbitol (30 g). The mixture was heated to 150 C. with agitation and NaOH (0.18 g) was added to catalyze alcoholysis of the melted soy titer by the polyol mixture. The mixture was heated from 150 C. to 220 C. with nitrogen sparging and good agitation over 1 hour. The product mixture enriched in fatty acid esters of polyols was then quickly cooled and neutralized with cone. H3PO4 (0.55 g). The cooled, neutralized product mixture separated into an upper phase containing the fatty acid esters of polyols and remaining titer esters and an aqueous bottom phase and the top phase solidified at room temperature. The solid top phase was collected and used in as a wax in a biobased candle wax formulation. |
Yield | Reaction Conditions | Operation in experiment |
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With potassium hydroxide; hydrogen;nickel-rhenium-on-carbon; In water; at 220℃; under 31029.7 - 62059.4 Torr; for 4h;Product distribution / selectivity; | Example 7Synthesis of PGME Enriched Polyol Esters of Soy OilThis Example sets forth a representative synthesis of a propylene glycol monoester from a vegetable oil and the hydrogenolysis product mixture from the hydrogenolysis of sorbitol.Sorbitol was subjected to hydrogenolysis substantially as set forth in Example 1. The hydrogenolysis product was then subjected to distillation to remove the water. The compositions of the hydrogenolysis product before and after stripping are set forth in Table 7. TABLE 7 Composition of Hydrogenolysis Product Hydrogenolysis product Hydrogenolysis product Compound before stripping (wt %) after stripping (wt %) Sorbitol 6.2% 10.0% Xylitol 2.2% 3.5% Erthyritol 0.8% 1.3% Lactate 1.0% 1.6% Glycerol 10.9% 17.6% 1,2,4-Butanetriol 0.5% 0.8% Ethylene glycol 11.4% 18.4% Propylene glycol 22.3% 36.0% 2,3-Butanediol 1.4% 2.3% 1,3-Butanediol 1.0% 1.6% 1,2-Butanediol 2.5% 4.0% Ethanol 0.4% 0.6% Isopropanol 0.2% 0.3% Water 38.0% 0% Unknown 1.2% 1.9% A 1 liter autoclave reactor was charged with RBD soybean oil (refined, bleached, and deodorized soybean oil, 160 g), the hydrogenolysis product mixture from sorbitol (165 g), potassium acetate (0.08 g), and lithium hydroxide (0.02 g). The reactor headspace was purged with nitrogen. The reactor was pressurized with nitrogen at 350 psi and agitation at 800 rpm was began. The reaction mixture was heated to 240 C. over 1 hour at which time the pressure has increased to 550 psi. The reaction was held at 240 C. for 1.5 hours and then rapidly cooled to room temperature. The contents of the reactor were placed in a separatory funnel and neutralized with 0.5 g of conc. H3PO4, The mixture was extracted with hexanes and the organic layer was washed once with four times its volume of deionized water. The organic layer was dried over anhydrous magnesium sulfate and filtered. The filtrate was concentrated with a rotary evaporator under reduced pressure to give a product having a Lovibond color of 2.9R., 14.0Y. The product composition was 60-81% propylene glycol monoester and 5% propylene glycol diester with an acid value of 21.6. This material may be used as a 100% biobased polyol ester replacement for petroleum derived PGMEs, for example as a coalescent in a latex paint formulation. |
Yield | Reaction Conditions | Operation in experiment |
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One (1) gram of xylitol (0.0066 mol) was introduced into a 100 ml three-neck round-bottomed flask. The flask was equipped with a stirrer, and heated in an oil bath to 80 C. The reaction was performed for 30 min with the pressure reduced to 25 mmHg by a vacuum aspirator to remove excessive moisture. A reaction catalyst, tin octoate (Tin (Oct) 2), dissolved in toluene was added into the glycerol. The reaction mixture was stirred for 30 minutes, and the pressure was reduced to 1 mmHg at 110 C. for 1 hour to remove the solvent (toluene) dissolving the catalyst. Purified lactide (31.7 g, 0.151 mol; 10 wt %) was added thereto, and the mixture was heated to 130 C. under the reduced pressure of 25 mmHg for 6 hours. The polymer formed was dissolved in acetone, and 0.2 N NaHCO3 aqueous solution was added dropwise thereto to precipitate the polymer. The precipitated polymer was washed three or four times with distilled water, isolated and dried under reduced pressure to obtain powder (5arm PLA-OH). |
Yield | Reaction Conditions | Operation in experiment |
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6%; 50% | With hydrogen; In water; at 60℃; under 12001.2 Torr; for 4h;Green chemistry;Catalytic behavior; | General procedure: Glucose and xylose hydrogenation reactions were carried out in a batch reactor (Amar equipments, India). The reactor was charged with 0.83 mmol of glucose or 1.00 mmol of xylose in 35 mL water. During reactions catalyst/substrate ratio was kept constant at 1:2 (wt/wt). When reactions were conducted using HT, 0.075 g of HT was added. Experiments were conducted at temperatures ranging between 60 C and 190 C under 8-24 bar of hydrogen pressure.The reactions were conducted for 2-6 h. Reaction mixture was analyzed using HPLC (Agilent, USA) equipped with HC-75 Pb++(9 m,7.8 mm × 300 mm) column. Water was used as an eluent, at the flow rate of 0.6 mL/min, and RID (model no. 1260 infinity) was used to detect the compounds. The products which are poorly separable by using HC-75 Pb++column, were analyzed using HPLC (Shimadzu,Japan) equipped with HC-75 H+(9 m, 7.8 mm × 305 mm) column. Succinic acid (0.5 mmol) is used as an eluent (0.5 mL/min). The refractive index detector (Model no. RID-6A) was used for the detection and calibration of compounds. The calibration of all the compounds was done using commercially available standards. |
With hydrogen; In water; at 120℃; under 41254.1 Torr; for 1h;Autoclave; Inert atmosphere; Green chemistry;Catalytic behavior; | The xylose hydrogenation experiments catalyzed by Ru/HYZwere carried out batch wise in 300 mL of three phase slurry reactorin the temperature range from 100 to 140 C at hydrogen pressure(2.0-5.5 MPa) by various stirring rate (400-1200 rpm). In typical hydrogenation experiment, required amount of catalyst (Ru/HYZ)and 100 mL of xylose solution were charged into stainless steel autoclave reactor. The reactor was fitted air tight and flushed with nitrogen gas three times at room temperature. Then, reactor was brought to desired temperature and pressurized with hydrogen which was considered as the zero reaction time. Hydrogenation reaction was initiated by stirring the entire reaction mass. Constant hydrogen pressure was maintained by supplying hydrogen gas manually through gas inlet valve during the reaction. During hydrogenation at different time intervals, the product components were analyzed using a HPLC (Younglin Instrument, Acme 9000)equipped with refractive index (RI) detector and Sugar-Pak column.De-ionized water was used as an eluent for the analysis at a flowrate of 0.4 mL/min at 70 C. After a stipulated period, the stirring was stopped and the reactor was abruptly cooled down, depressurized,flushed with N2, opened and decanted the reaction mixture from the catalyst to collect sample for final analysis. Xylose (XLS) conversion, selectivity to main xylitol (XTL) and arabitol (ARB) are calculated using following expressions. XLSConv. (%)=(1- mole of xylose at particular time/initial mole of xylose)×100 XTLSelc. (%)=(mole of XTL/mole of all products formed)×100 ARBSelc. (%)=(mole of ARB/mole of all products formed)×100 |
Yield | Reaction Conditions | Operation in experiment |
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83.03% | With sulfuric acid; ruthenium-carbon composite; In water; isopropyl alcohol; at 140℃; for 3h; | Here, the effects of different amounts of the Ru/C catalyst on the synthesis of xylitol were investigated. 67.77mg hemicellulose (0.513 mmol D-xylose unit), varyingamounts of Ru/C (2.4 mol%), 4 ml water, 4 ml iso-propanol and 7 jil H2S04 were mixed in a lOmi Teflon-lined hydrothermal reactor and reacted at a temperature of 14 0C for 3 hours. The reactor was heated to 140C using a silicon oil bath or an oven and maintained at thistemperature for 3 hours with magnetic stirring at 600 rpm. After the reaction, the reactor was naturally cooled down. |
Yield | Reaction Conditions | Operation in experiment |
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With hydrogen; In water; at 120℃; under 60006 Torr; for 6h; | Samples 10, 11, 14, 19 and 20 were evaluated for xylose hydrogenation in a batch reactor. Before reaction, the catalysts were reduced in-situ at 450 C. for 4 h with a heating ramp rate of 3 K/min. The test was conducted under 80 bar hydrogen pressure at 120 C. for 6 h. The catalyst loading was about 5 mL (about 5.1-5.5 g) in each test. The feed contained about 10 wt % xylose (food grade) aqueous solution with total about 100 mL in volume. The conversion efficiency and selectivity for xylitol was determined as follows: (0082) Conversion = mol . of xylose consumd mol . of xylose input × 100 % S xylitol = mol . of xylitol produced × 5 mol . of xylose consumed × 5 × 100 % (0083) The conversion and xylitol selectivity from xylose hydrogenation after 6 h is shown in Table 6. For all the catalyst materials, the conversion was high (above 98%), but the xylitol selectivity varied. NiCu catalyst material showed a higher selectivity compared to Ni catalyst material; for example, NiCu-ZrO2/MnOx (Sample 14) showed about 99.9% xylitol selectivity while Ni-ZrO2/MnOx (Sample 20) showed about 90.9% xylitol selectivity, where the catalysts were prepared based on the same carrier. The carbon selectivity to xylitol dropped significantly from 90.9% for Sample 20 to only 50% for Sample 19, both of which are Ni-ZrO2/MnOX materials but the later had a much higher Mn loading. For Sample 19, about 12% GYL selectivity, about 10% EG selectivity, and about 10% PG selectivity were observed in the final product, and the other carbon was possibly lost as coke and in gas. |
Yield | Reaction Conditions | Operation in experiment |
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General procedure: Samples of polysaccharides FCp-1 to FCp-4 (each 5mg) were hydrolyzed in 2M trifluoroacetic acid (TFA; 5mL) at 120C for 6h, and then evaporated to dryness under reduced pressure. The residue was divided into two portions. One portion was used for paper chromatography (PC), which was performed on Whatman 3MM filter paper, eluting with either (a) EtOAc/HOAc/H2O (3:3:1) or (b) n-BuOH/pyridine/H2O (6:4:3) solvent systems. Papers were visualized by aniline-diphenylamine-phosphoric acid solution (a) or p-anisidine solution (b),15 and authentic standards (l-arabinose, d-glucose, d-mannose, d-galactose, d-ribose, d-xylose, l-rhamnose, d-glucuronic acid and d-galactonic acid) were used as reference compounds. The other portion of crude residue was treated with NaBH4 (15mg), and the resulting mixture stirred at room temperature for 12h. The reaction mixture was then treated with a mixture of Ac2O and pyridine (1.0mL of each) at 120 C for 6h,16 and then concentrated to dryness under reduced pressure. The resulting alditol acetates were re-dissolved in CH2Cl2 (1mL) for GC-MS analysis, from which their structures were identified by their retention times and electron-impact profiles. |
Yield | Reaction Conditions | Operation in experiment |
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With water; hydrogen at 210℃; for 0.5h; Autoclave; | Cellulose reaction General procedure: Cellulose (microcrystalline, Alfa Aesar) reactions were carried out in a stainless steel autoclave (100mL) typically at 210°C and 6MPa H2 for 30min with vigorous stirring at a speed of 800rpm. In a typical run, 1g cellulose and 0.4g catalyst were introduced into the autoclave containing 50mL H2O. Afterwards, the reactor was fully purged with H2 (>99.999%, Beijing Longhui Jingcheng), pressurized with H2 to 6.0MPa and then heated to 210°C which was kept constant during the reaction. After cooling to room temperature in water, the reaction mixture was filtrated and the solids were washed several times with deionized water. The solids including the catalyst and remaining cellulose were washed with acetone three times and then fully dried in an oven at 60°C for 24h. Cellulose conversions were determined by the change in the weight of cellulose loaded before and after the reactions. The products in the liquid phase (e.g. polyols) were analyzed by high-performance liquid chromatography (Shimadzu LC-20A) using Bio-Rad Aminex HPX-87H with a RID detector. The product selectivities were reported on a carbon basis. |
Yield | Reaction Conditions | Operation in experiment |
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With water; hydrogen at 210℃; for 0.5h; Autoclave; | Cellulose reaction General procedure: Cellulose (microcrystalline, Alfa Aesar) reactions were carried out in a stainless steel autoclave (100mL) typically at 210°C and 6MPa H2 for 30min with vigorous stirring at a speed of 800rpm. In a typical run, 1g cellulose and 0.4g catalyst were introduced into the autoclave containing 50mL H2O. Afterwards, the reactor was fully purged with H2 (>99.999%, Beijing Longhui Jingcheng), pressurized with H2 to 6.0MPa and then heated to 210°C which was kept constant during the reaction. After cooling to room temperature in water, the reaction mixture was filtrated and the solids were washed several times with deionized water. The solids including the catalyst and remaining cellulose were washed with acetone three times and then fully dried in an oven at 60°C for 24h. Cellulose conversions were determined by the change in the weight of cellulose loaded before and after the reactions. The products in the liquid phase (e.g. polyols) were analyzed by high-performance liquid chromatography (Shimadzu LC-20A) using Bio-Rad Aminex HPX-87H with a RID detector. The product selectivities were reported on a carbon basis. |
Yield | Reaction Conditions | Operation in experiment |
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With water; hydrogen at 210℃; for 0.5h; Autoclave; | Cellulose reaction General procedure: Cellulose (microcrystalline, Alfa Aesar) reactions were carried out in a stainless steel autoclave (100mL) typically at 210°C and 6MPa H2 for 30min with vigorous stirring at a speed of 800rpm. In a typical run, 1g cellulose and 0.4g catalyst were introduced into the autoclave containing 50mL H2O. Afterwards, the reactor was fully purged with H2 (>99.999%, Beijing Longhui Jingcheng), pressurized with H2 to 6.0MPa and then heated to 210°C which was kept constant during the reaction. After cooling to room temperature in water, the reaction mixture was filtrated and the solids were washed several times with deionized water. The solids including the catalyst and remaining cellulose were washed with acetone three times and then fully dried in an oven at 60°C for 24h. Cellulose conversions were determined by the change in the weight of cellulose loaded before and after the reactions. The products in the liquid phase (e.g. polyols) were analyzed by high-performance liquid chromatography (Shimadzu LC-20A) using Bio-Rad Aminex HPX-87H with a RID detector. The product selectivities were reported on a carbon basis. |
Yield | Reaction Conditions | Operation in experiment |
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With water; hydrogen at 210℃; for 1h; | Cellulose reaction General procedure: Cellulose (microcrystalline, Alfa Aesar) reactions were carried out in a stainless steel autoclave (100mL) typically at 210°C and 6MPa H2 for 30min with vigorous stirring at a speed of 800rpm. In a typical run, 1g cellulose and 0.4g catalyst were introduced into the autoclave containing 50mL H2O. Afterwards, the reactor was fully purged with H2 (>99.999%, Beijing Longhui Jingcheng), pressurized with H2 to 6.0MPa and then heated to 210°C which was kept constant during the reaction. After cooling to room temperature in water, the reaction mixture was filtrated and the solids were washed several times with deionized water. The solids including the catalyst and remaining cellulose were washed with acetone three times and then fully dried in an oven at 60°C for 24h. Cellulose conversions were determined by the change in the weight of cellulose loaded before and after the reactions. The products in the liquid phase (e.g. polyols) were analyzed by high-performance liquid chromatography (Shimadzu LC-20A) using Bio-Rad Aminex HPX-87H with a RID detector. The product selectivities were reported on a carbon basis. |
Yield | Reaction Conditions | Operation in experiment |
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With water; hydrogen at 210℃; for 1h; | Cellulose reaction General procedure: Cellulose (microcrystalline, Alfa Aesar) reactions were carried out in a stainless steel autoclave (100mL) typically at 210°C and 6MPa H2 for 30min with vigorous stirring at a speed of 800rpm. In a typical run, 1g cellulose and 0.4g catalyst were introduced into the autoclave containing 50mL H2O. Afterwards, the reactor was fully purged with H2 (>99.999%, Beijing Longhui Jingcheng), pressurized with H2 to 6.0MPa and then heated to 210°C which was kept constant during the reaction. After cooling to room temperature in water, the reaction mixture was filtrated and the solids were washed several times with deionized water. The solids including the catalyst and remaining cellulose were washed with acetone three times and then fully dried in an oven at 60°C for 24h. Cellulose conversions were determined by the change in the weight of cellulose loaded before and after the reactions. The products in the liquid phase (e.g. polyols) were analyzed by high-performance liquid chromatography (Shimadzu LC-20A) using Bio-Rad Aminex HPX-87H with a RID detector. The product selectivities were reported on a carbon basis. |
Yield | Reaction Conditions | Operation in experiment |
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With water; hydrogen at 210℃; for 1h; | Cellulose reaction General procedure: Cellulose (microcrystalline, Alfa Aesar) reactions were carried out in a stainless steel autoclave (100mL) typically at 210°C and 6MPa H2 for 30min with vigorous stirring at a speed of 800rpm. In a typical run, 1g cellulose and 0.4g catalyst were introduced into the autoclave containing 50mL H2O. Afterwards, the reactor was fully purged with H2 (>99.999%, Beijing Longhui Jingcheng), pressurized with H2 to 6.0MPa and then heated to 210°C which was kept constant during the reaction. After cooling to room temperature in water, the reaction mixture was filtrated and the solids were washed several times with deionized water. The solids including the catalyst and remaining cellulose were washed with acetone three times and then fully dried in an oven at 60°C for 24h. Cellulose conversions were determined by the change in the weight of cellulose loaded before and after the reactions. The products in the liquid phase (e.g. polyols) were analyzed by high-performance liquid chromatography (Shimadzu LC-20A) using Bio-Rad Aminex HPX-87H with a RID detector. The product selectivities were reported on a carbon basis. |
Yield | Reaction Conditions | Operation in experiment |
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With water; hydrogen at 210℃; for 0.5h; Autoclave; | Cellulose reaction General procedure: Cellulose (microcrystalline, Alfa Aesar) reactions were carried out in a stainless steel autoclave (100mL) typically at 210°C and 6MPa H2 for 30min with vigorous stirring at a speed of 800rpm. In a typical run, 1g cellulose and 0.4g catalyst were introduced into the autoclave containing 50mL H2O. Afterwards, the reactor was fully purged with H2 (>99.999%, Beijing Longhui Jingcheng), pressurized with H2 to 6.0MPa and then heated to 210°C which was kept constant during the reaction. After cooling to room temperature in water, the reaction mixture was filtrated and the solids were washed several times with deionized water. The solids including the catalyst and remaining cellulose were washed with acetone three times and then fully dried in an oven at 60°C for 24h. Cellulose conversions were determined by the change in the weight of cellulose loaded before and after the reactions. The products in the liquid phase (e.g. polyols) were analyzed by high-performance liquid chromatography (Shimadzu LC-20A) using Bio-Rad Aminex HPX-87H with a RID detector. The product selectivities were reported on a carbon basis. |
Yield | Reaction Conditions | Operation in experiment |
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With water; hydrogen at 210℃; for 0.5h; Autoclave; | Cellulose reaction General procedure: Cellulose (microcrystalline, Alfa Aesar) reactions were carried out in a stainless steel autoclave (100mL) typically at 210°C and 6MPa H2 for 30min with vigorous stirring at a speed of 800rpm. In a typical run, 1g cellulose and 0.4g catalyst were introduced into the autoclave containing 50mL H2O. Afterwards, the reactor was fully purged with H2 (>99.999%, Beijing Longhui Jingcheng), pressurized with H2 to 6.0MPa and then heated to 210°C which was kept constant during the reaction. After cooling to room temperature in water, the reaction mixture was filtrated and the solids were washed several times with deionized water. The solids including the catalyst and remaining cellulose were washed with acetone three times and then fully dried in an oven at 60°C for 24h. Cellulose conversions were determined by the change in the weight of cellulose loaded before and after the reactions. The products in the liquid phase (e.g. polyols) were analyzed by high-performance liquid chromatography (Shimadzu LC-20A) using Bio-Rad Aminex HPX-87H with a RID detector. The product selectivities were reported on a carbon basis. |
Yield | Reaction Conditions | Operation in experiment |
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With water; hydrogen at 210℃; for 0.5h; Autoclave; | Cellulose reaction General procedure: Cellulose (microcrystalline, Alfa Aesar) reactions were carried out in a stainless steel autoclave (100mL) typically at 210°C and 6MPa H2 for 30min with vigorous stirring at a speed of 800rpm. In a typical run, 1g cellulose and 0.4g catalyst were introduced into the autoclave containing 50mL H2O. Afterwards, the reactor was fully purged with H2 (>99.999%, Beijing Longhui Jingcheng), pressurized with H2 to 6.0MPa and then heated to 210°C which was kept constant during the reaction. After cooling to room temperature in water, the reaction mixture was filtrated and the solids were washed several times with deionized water. The solids including the catalyst and remaining cellulose were washed with acetone three times and then fully dried in an oven at 60°C for 24h. Cellulose conversions were determined by the change in the weight of cellulose loaded before and after the reactions. The products in the liquid phase (e.g. polyols) were analyzed by high-performance liquid chromatography (Shimadzu LC-20A) using Bio-Rad Aminex HPX-87H with a RID detector. The product selectivities were reported on a carbon basis. |
Yield | Reaction Conditions | Operation in experiment |
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With hydrogen at 140℃; |
Yield | Reaction Conditions | Operation in experiment |
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With hydrogen; In water; at 159.84℃; under 37503.8 Torr; for 10h; | The one-pot conversion of cellobiose and microcrystalline cellulose into hexitols was conducted in a lab-scale batch reactorwith a Teflon insert (20 mL) heated in an oil bath and stirred byan electromagnetic stick. In a typical catalytic reaction run, 0.25 gmicrocrystalline cellulose or cellobiose, 0.05 g catalyst and 5 mL deionized water were added to the reactor. The reactor was thenflushed with hydrogen to 5 MPa and heated to the desired reac-tion temperature (measured in the Teflon insert). After reaction,the reactor was quickly cooled in an ice bath. The solid residual con-taining the catalyst and unreacted cellulose were separated fromthe liquid product using centrifugation. The liquid products werequantified using HPLC equipped with a refractive index detectorand ICSep Coregel-87H column. An aqueous solution of H2SO4 at 0.005 M with a flow rate of 0.6 mL/min was used as the mobilephase. A series of calibration standards with different concentra-tions have been prepared and measured with the same column onthe HPLC. By comparing the retention time and peak area of thesample with that of the calibration standards under the same con-dition, a particular component of the liquid products correspondingto each peak can be determined. The amount of the product can bequantified with the peak area by referring to the standard curve. TheHPLC column used in the present study can identify and quantifysoluble saccharides (sucrose, fructose, xylose, etc.), C1-C6 alcohol(methanol, propanediol, sorbitol, etc.), carboxylic acids (lactic acid,levulinic acid, formic acid, etc.), carbonyls (formaldehyde, acetalde-hyde) and some other small organic molecules. The solid residualcontaining the catalyst and the unreacted cellulose were driedovernight before being weighed. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With hydrogen; In water; at 159.84℃; under 37503.8 Torr; for 10h; | General procedure: The one-pot conversion of cellobiose and microcrystalline cellulose into hexitols was conducted in a lab-scale batch reactorwith a Teflon insert (20 mL) heated in an oil bath and stirred byan electromagnetic stick. In a typical catalytic reaction run, 0.25 gmicrocrystalline cellulose or cellobiose, 0.05 g catalyst and 5 mL deionized water were added to the reactor. The reactor was thenflushed with hydrogen to 5 MPa and heated to the desired reac-tion temperature (measured in the Teflon insert). After reaction,the reactor was quickly cooled in an ice bath. The solid residual con-taining the catalyst and unreacted cellulose were separated fromthe liquid product using centrifugation. The liquid products werequantified using HPLC equipped with a refractive index detectorand ICSep Coregel-87H column. An aqueous solution of H2SO4 at 0.005 M with a flow rate of 0.6 mL/min was used as the mobilephase. A series of calibration standards with different concentra-tions have been prepared and measured with the same column onthe HPLC. By comparing the retention time and peak area of thesample with that of the calibration standards under the same con-dition, a particular component of the liquid products correspondingto each peak can be determined. The amount of the product can bequantified with the peak area by referring to the standard curve. TheHPLC column used in the present study can identify and quantifysoluble saccharides (sucrose, fructose, xylose, etc.), C1-C6 alcohol(methanol, propanediol, sorbitol, etc.), carboxylic acids (lactic acid,levulinic acid, formic acid, etc.), carbonyls (formaldehyde, acetalde-hyde) and some other small organic molecules. The solid residualcontaining the catalyst and the unreacted cellulose were driedovernight before being weighed. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With hydrogen; at 199.84℃; under 30003 Torr; for 3h;Autoclave; | General procedure: Xylitol hydrogenolysis reactions were carried out in a stainlesssteel autoclave (100 ml) at a stirring speed of 800 rpm. Typically,40 g of 10 wt% xylitol (99%, Alfa Aesar) aqueous solution, properamount of Ni catalysts (varied depending on xylitol conversion)and also for the Ni/C case, solid base were introduced to the auto-clave. Afterwards, the reactor was purged with H2(>99.99%, BeijingHuayuan) three times, and pressurized with H2to 4.0 MPa andheated to 473 K, which was kept constant during the reaction.The reactant and liquid products, after silylation with hexame-thyldisilazane (HDMS) and trimethylchlorosilane (TMSCl) (both?98.0%, Sinopharm Chemical) in pyridine (AR, Shantou XilongChemical), were analyzed by gas chromatography (Agilent 7890A)using a capillary column HP-1ms (30 m × 0.25 mm × 0.25 m) anda flame ionization detector. The detected liquid products includedethylene glycol, propylene glycol, glycerol, lactic acid, threitol,arabitol, and dehydroxy-pentitols (mainly 1,2,5-pentanetriol and1,2,4,5-pentanetetraol), and dehydrated product hydroxyl furan.Gas products, i.e. CH4and CO2, were also detected in trace amounts,and thus not discussed in this work. Xylitol conversion and productselectivity are reported on a carbon basis, and xylitol reaction activ-ity is reported as molar xylitol conversion rate per mole of metalloaded per hour (h-1). |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With cerium(IV) oxide; hydrogen at 199.84℃; for 3h; Autoclave; | General procedure: Xylitol hydrogenolysis reactions were carried out in a stainlesssteel autoclave (100 ml) at a stirring speed of 800 rpm. Typically,40 g of 10 wt% xylitol (99%, Alfa Aesar) aqueous solution, properamount of Ni catalysts (varied depending on xylitol conversion)and also for the Ni/C case, solid base were introduced to the auto-clave. Afterwards, the reactor was purged with H2(>99.99%, BeijingHuayuan) three times, and pressurized with H2to 4.0 MPa andheated to 473 K, which was kept constant during the reaction.The reactant and liquid products, after silylation with hexame-thyldisilazane (HDMS) and trimethylchlorosilane (TMSCl) (both≥98.0%, Sinopharm Chemical) in pyridine (AR, Shantou XilongChemical), were analyzed by gas chromatography (Agilent 7890A)using a capillary column HP-1ms (30 m × 0.25 mm × 0.25 m) anda flame ionization detector. The detected liquid products includedethylene glycol, propylene glycol, glycerol, lactic acid, threitol,arabitol, and dehydroxy-pentitols (mainly 1,2,5-pentanetriol and1,2,4,5-pentanetetraol), and dehydrated product hydroxyl furan.Gas products, i.e. CH4and CO2, were also detected in trace amounts,and thus not discussed in this work. Xylitol conversion and productselectivity are reported on a carbon basis, and xylitol reaction activ-ity is reported as molar xylitol conversion rate per mole of metalloaded per hour (h-1). | |
With hydrogen at 199.84℃; for 3h; Autoclave; | General procedure: Xylitol hydrogenolysis reactions were carried out in a stainlesssteel autoclave (100 ml) at a stirring speed of 800 rpm. Typically,40 g of 10 wt% xylitol (99%, Alfa Aesar) aqueous solution, properamount of Ni catalysts (varied depending on xylitol conversion)and also for the Ni/C case, solid base were introduced to the auto-clave. Afterwards, the reactor was purged with H2(>99.99%, BeijingHuayuan) three times, and pressurized with H2to 4.0 MPa andheated to 473 K, which was kept constant during the reaction.The reactant and liquid products, after silylation with hexame-thyldisilazane (HDMS) and trimethylchlorosilane (TMSCl) (both≥98.0%, Sinopharm Chemical) in pyridine (AR, Shantou XilongChemical), were analyzed by gas chromatography (Agilent 7890A)using a capillary column HP-1ms (30 m × 0.25 mm × 0.25 m) anda flame ionization detector. The detected liquid products includedethylene glycol, propylene glycol, glycerol, lactic acid, threitol,arabitol, and dehydroxy-pentitols (mainly 1,2,5-pentanetriol and1,2,4,5-pentanetetraol), and dehydrated product hydroxyl furan.Gas products, i.e. CH4and CO2, were also detected in trace amounts,and thus not discussed in this work. Xylitol conversion and productselectivity are reported on a carbon basis, and xylitol reaction activ-ity is reported as molar xylitol conversion rate per mole of metalloaded per hour (h-1). |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With aluminum oxide; hydrogen; at 199.84℃; under 30003 Torr; for 3h;Autoclave; | General procedure: Xylitol hydrogenolysis reactions were carried out in a stainlesssteel autoclave (100 ml) at a stirring speed of 800 rpm. Typically,40 g of 10 wt% xylitol (99%, Alfa Aesar) aqueous solution, properamount of Ni catalysts (varied depending on xylitol conversion)and also for the Ni/C case, solid base were introduced to the auto-clave. Afterwards, the reactor was purged with H2(>99.99%, BeijingHuayuan) three times, and pressurized with H2to 4.0 MPa andheated to 473 K, which was kept constant during the reaction.The reactant and liquid products, after silylation with hexame-thyldisilazane (HDMS) and trimethylchlorosilane (TMSCl) (both?98.0%, Sinopharm Chemical) in pyridine (AR, Shantou XilongChemical), were analyzed by gas chromatography (Agilent 7890A)using a capillary column HP-1ms (30 m × 0.25 mm × 0.25 m) anda flame ionization detector. The detected liquid products includedethylene glycol, propylene glycol, glycerol, lactic acid, threitol,arabitol, and dehydroxy-pentitols (mainly 1,2,5-pentanetriol and1,2,4,5-pentanetetraol), and dehydrated product hydroxyl furan.Gas products, i.e. CH4and CO2, were also detected in trace amounts,and thus not discussed in this work. Xylitol conversion and productselectivity are reported on a carbon basis, and xylitol reaction activ-ity is reported as molar xylitol conversion rate per mole of metalloaded per hour (h-1). | |
With hydrogen; zirconium(IV) oxide; at 199.84℃; under 30003 Torr; for 3h;Autoclave; | General procedure: Xylitol hydrogenolysis reactions were carried out in a stainlesssteel autoclave (100 ml) at a stirring speed of 800 rpm. Typically,40 g of 10 wt% xylitol (99%, Alfa Aesar) aqueous solution, properamount of Ni catalysts (varied depending on xylitol conversion)and also for the Ni/C case, solid base were introduced to the auto-clave. Afterwards, the reactor was purged with H2(>99.99%, BeijingHuayuan) three times, and pressurized with H2to 4.0 MPa andheated to 473 K, which was kept constant during the reaction.The reactant and liquid products, after silylation with hexame-thyldisilazane (HDMS) and trimethylchlorosilane (TMSCl) (both?98.0%, Sinopharm Chemical) in pyridine (AR, Shantou XilongChemical), were analyzed by gas chromatography (Agilent 7890A)using a capillary column HP-1ms (30 m × 0.25 mm × 0.25 m) anda flame ionization detector. The detected liquid products includedethylene glycol, propylene glycol, glycerol, lactic acid, threitol,arabitol, and dehydroxy-pentitols (mainly 1,2,5-pentanetriol and1,2,4,5-pentanetetraol), and dehydrated product hydroxyl furan.Gas products, i.e. CH4and CO2, were also detected in trace amounts,and thus not discussed in this work. Xylitol conversion and productselectivity are reported on a carbon basis, and xylitol reaction activ-ity is reported as molar xylitol conversion rate per mole of metalloaded per hour (h-1). | |
With hydrogen; calcium carbonate; at 199.84℃; under 30003 Torr; for 3h;Autoclave; | General procedure: Xylitol hydrogenolysis reactions were carried out in a stainlesssteel autoclave (100 ml) at a stirring speed of 800 rpm. Typically,40 g of 10 wt% xylitol (99%, Alfa Aesar) aqueous solution, properamount of Ni catalysts (varied depending on xylitol conversion)and also for the Ni/C case, solid base were introduced to the auto-clave. Afterwards, the reactor was purged with H2(>99.99%, BeijingHuayuan) three times, and pressurized with H2to 4.0 MPa andheated to 473 K, which was kept constant during the reaction.The reactant and liquid products, after silylation with hexame-thyldisilazane (HDMS) and trimethylchlorosilane (TMSCl) (both?98.0%, Sinopharm Chemical) in pyridine (AR, Shantou XilongChemical), were analyzed by gas chromatography (Agilent 7890A)using a capillary column HP-1ms (30 m × 0.25 mm × 0.25 m) anda flame ionization detector. The detected liquid products includedethylene glycol, propylene glycol, glycerol, lactic acid, threitol,arabitol, and dehydroxy-pentitols (mainly 1,2,5-pentanetriol and1,2,4,5-pentanetetraol), and dehydrated product hydroxyl furan.Gas products, i.e. CH4and CO2, were also detected in trace amounts,and thus not discussed in this work. Xylitol conversion and productselectivity are reported on a carbon basis, and xylitol reaction activ-ity is reported as molar xylitol conversion rate per mole of metalloaded per hour (h-1). |
With hydrogen; at 199.84℃; under 30003 Torr; for 3h;Autoclave; | General procedure: Xylitol hydrogenolysis reactions were carried out in a stainlesssteel autoclave (100 ml) at a stirring speed of 800 rpm. Typically,40 g of 10 wt% xylitol (99%, Alfa Aesar) aqueous solution, properamount of Ni catalysts (varied depending on xylitol conversion)and also for the Ni/C case, solid base were introduced to the auto-clave. Afterwards, the reactor was purged with H2(>99.99%, BeijingHuayuan) three times, and pressurized with H2to 4.0 MPa andheated to 473 K, which was kept constant during the reaction.The reactant and liquid products, after silylation with hexame-thyldisilazane (HDMS) and trimethylchlorosilane (TMSCl) (both?98.0%, Sinopharm Chemical) in pyridine (AR, Shantou XilongChemical), were analyzed by gas chromatography (Agilent 7890A)using a capillary column HP-1ms (30 m × 0.25 mm × 0.25 m) anda flame ionization detector. The detected liquid products includedethylene glycol, propylene glycol, glycerol, lactic acid, threitol,arabitol, and dehydroxy-pentitols (mainly 1,2,5-pentanetriol and1,2,4,5-pentanetetraol), and dehydrated product hydroxyl furan.Gas products, i.e. CH4and CO2, were also detected in trace amounts,and thus not discussed in this work. Xylitol conversion and productselectivity are reported on a carbon basis, and xylitol reaction activ-ity is reported as molar xylitol conversion rate per mole of metalloaded per hour (h-1). |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With hydrogen at 199.84℃; for 3h; Autoclave; | General procedure: Xylitol hydrogenolysis reactions were carried out in a stainlesssteel autoclave (100 ml) at a stirring speed of 800 rpm. Typically,40 g of 10 wt% xylitol (99%, Alfa Aesar) aqueous solution, properamount of Ni catalysts (varied depending on xylitol conversion)and also for the Ni/C case, solid base were introduced to the auto-clave. Afterwards, the reactor was purged with H2(>99.99%, BeijingHuayuan) three times, and pressurized with H2to 4.0 MPa andheated to 473 K, which was kept constant during the reaction.The reactant and liquid products, after silylation with hexame-thyldisilazane (HDMS) and trimethylchlorosilane (TMSCl) (both≥98.0%, Sinopharm Chemical) in pyridine (AR, Shantou XilongChemical), were analyzed by gas chromatography (Agilent 7890A)using a capillary column HP-1ms (30 m × 0.25 mm × 0.25 m) anda flame ionization detector. The detected liquid products includedethylene glycol, propylene glycol, glycerol, lactic acid, threitol,arabitol, and dehydroxy-pentitols (mainly 1,2,5-pentanetriol and1,2,4,5-pentanetetraol), and dehydrated product hydroxyl furan.Gas products, i.e. CH4and CO2, were also detected in trace amounts,and thus not discussed in this work. Xylitol conversion and productselectivity are reported on a carbon basis, and xylitol reaction activ-ity is reported as molar xylitol conversion rate per mole of metalloaded per hour (h-1). |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With hydrogen at 199.84℃; for 2h; Autoclave; | General procedure: Xylitol hydrogenolysis reactions were carried out in a stainlesssteel autoclave (100 ml) at a stirring speed of 800 rpm. Typically,40 g of 10 wt% xylitol (99%, Alfa Aesar) aqueous solution, properamount of Ni catalysts (varied depending on xylitol conversion)and also for the Ni/C case, solid base were introduced to the auto-clave. Afterwards, the reactor was purged with H2(>99.99%, BeijingHuayuan) three times, and pressurized with H2to 4.0 MPa andheated to 473 K, which was kept constant during the reaction.The reactant and liquid products, after silylation with hexame-thyldisilazane (HDMS) and trimethylchlorosilane (TMSCl) (both≥98.0%, Sinopharm Chemical) in pyridine (AR, Shantou XilongChemical), were analyzed by gas chromatography (Agilent 7890A)using a capillary column HP-1ms (30 m × 0.25 mm × 0.25 m) anda flame ionization detector. The detected liquid products includedethylene glycol, propylene glycol, glycerol, lactic acid, threitol,arabitol, and dehydroxy-pentitols (mainly 1,2,5-pentanetriol and1,2,4,5-pentanetetraol), and dehydrated product hydroxyl furan.Gas products, i.e. CH4and CO2, were also detected in trace amounts,and thus not discussed in this work. Xylitol conversion and productselectivity are reported on a carbon basis, and xylitol reaction activ-ity is reported as molar xylitol conversion rate per mole of metalloaded per hour (h-1). |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With hydrogen; calcium hydroxide at 199.84℃; for 1h; Autoclave; | General procedure: Xylitol hydrogenolysis reactions were carried out in a stainlesssteel autoclave (100 ml) at a stirring speed of 800 rpm. Typically,40 g of 10 wt% xylitol (99%, Alfa Aesar) aqueous solution, properamount of Ni catalysts (varied depending on xylitol conversion)and also for the Ni/C case, solid base were introduced to the auto-clave. Afterwards, the reactor was purged with H2(>99.99%, BeijingHuayuan) three times, and pressurized with H2to 4.0 MPa andheated to 473 K, which was kept constant during the reaction.The reactant and liquid products, after silylation with hexame-thyldisilazane (HDMS) and trimethylchlorosilane (TMSCl) (both≥98.0%, Sinopharm Chemical) in pyridine (AR, Shantou XilongChemical), were analyzed by gas chromatography (Agilent 7890A)using a capillary column HP-1ms (30 m × 0.25 mm × 0.25 m) anda flame ionization detector. The detected liquid products includedethylene glycol, propylene glycol, glycerol, lactic acid, threitol,arabitol, and dehydroxy-pentitols (mainly 1,2,5-pentanetriol and1,2,4,5-pentanetetraol), and dehydrated product hydroxyl furan.Gas products, i.e. CH4and CO2, were also detected in trace amounts,and thus not discussed in this work. Xylitol conversion and productselectivity are reported on a carbon basis, and xylitol reaction activ-ity is reported as molar xylitol conversion rate per mole of metalloaded per hour (h-1). |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With sodium tetrahydroborate; sodium hydroxide;pH 7; | General procedure: Compounds (10 mg) was heated in an ampule along with 5 mL of aqueous 12% HCl at 90 for 2h. The aglycone was extracted with chloroform, and each aqueous residue was adjusted to pH 7.0 with12% NaOH and reduced with NaBH4 (40 mg), followed by acidification with dilute CH3COOH, andthen co-distilled with pure CH3OH to remove excess boric acid. The reduced sugars were acetylated with 1:1 pyridine-Ac2O in a boiling water bath for 2 h to give the alditol acetates, which were analyzedby GLC performed with a HP 6890 N gas chromatograph (Agilent, American) equipped with a flameionization detector. The instrument was fitted with a HP-5 capillary column (30 m × 0.32 mm × 0.25mm) by FID detector with N2 as carrier gas. The injector temperature was set at 250 and the columntemperature program was as follows: the initial temperature of 120 was increased by 38/min to thefinal temperature of 210 , then was held 4 min. The detector temperature was set at 300 . Thestandard monosaccharides were subjected to the same reaction and GC analysis under the sameconditions (D-galactose, tR, 25 min; D-xylose, tR, 19 min). | |
With sodium tetrahydroborate; In methanol; at 20℃; for 1h; | General procedure: TheGC-MSanalysis of the sugar moieties has been previously described by Scognamiglio et al. [31].Briefly, each metabolite (0.5 mg) was subjected to an acid hydrolysis with 2 N TFA (150 muL) at 120 Cfor 1 h, obtaining the sugar moiety. This was dried under N2 flow, and reduced by adding MeOH(150 muL) and NaBH4 (1.0 mg). The solution was incubated at room temperature for 1 h and then driedunder N2 flow after treatment with glacial AcOH and MeOH. The obtained alditol was acetylatedby using anhydrous pyridine (200 muL) and Ac2O (200 muL). This mixture was incubated for 20 minat 120 C. Then, 500 muL of H2O was added, and the product was extracted with CH2Cl2 (500 muL)following centrifugation at 3500 rpm for 5 min. The organic phase was dried under N2 flow, dissolvedin CH2Cl2 (500 muL) and analyzed by GC-MS. Temperature conditions were as follows: Injector port at250 C; the initial oven temperature was 160 C for 50 s, then linearly increased to 200 C at 10 C/min.A further linear increase at 2.5 C/min was performed to 300 C, and held for 40 min. Sample solutionswere injected using the split mode. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
1: 66% 2: 8% | With Butane-1,4-diol; Cu3Ni3Al2 In water at 149.84℃; |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With 5% active carbon-supported ruthenium; hydrogen In water at 199.84℃; for 4h; Autoclave; |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With 5% active carbon-supported ruthenium; hydrogen In water at 199.84℃; for 2h; Autoclave; |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With 5% active carbon-supported ruthenium; hydrogen In water at 219.84℃; for 4h; Autoclave; |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With 5% active carbon-supported ruthenium; hydrogen In water at 179.84℃; for 4h; Autoclave; |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With 5% active carbon-supported ruthenium; hydrogen In water at 219.84℃; for 4h; Autoclave; |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With 5% active carbon-supported ruthenium; hydrogen In water at 179.84℃; for 4h; Autoclave; |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With 5% active carbon-supported ruthenium; hydrogen In water at 140℃; for 1h; Autoclave; |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With 5% active carbon-supported ruthenium; hydrogen In water at 140℃; for 19h; Autoclave; |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With 5% active carbon-supported ruthenium; hydrogen In water at 140℃; for 4h; Autoclave; |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With 5% active carbon-supported ruthenium; hydrogen In water at 149.84℃; for 3h; |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With Ru/C; hydrogen; In water; at 204.84℃; under 45004.5 Torr; for 0.5h;Autoclave; | General procedure: Cellulose (microcrystalline, Alfa Aesar) reactions were carriedout in 40 mL water in a stainless steel autoclave (100 mL), typicallyat 478 K and 6 MPa H2for 30 min with vigorous agitation. Celluloseconversions were determined according to the difference in theweight of cellulose before and after the reactions. The products (e.g.polyols) were analyzed by high-performance liquid chromatogra-phy (Shimadzu LC-20A) equipped with an RID detector (RID-20A),using a Bio-rad HPX-87C column. Gas products were analyzed by GC(Shimadzu 2010GC) using an HJ-OV-101 column connected to anFID detector. Product selectivity was calculated on a carbon basis. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
70% | With hydrogenchloride; In methanol; water; at 20℃; for 8h; | At room temperature, to a 1L 4-neck flask equipped with mechanical stirrer, a thermometer was added D-xylitol 16.7g (0.11mol),methanol 20mL, water 20ml, concentrated hydrochloric acid 10mL, 220 rev / min stirring speed. Add dropwise p-formylbenzoic acid methyl ester solution (8.97g(0.055mol) of p-formylbenzoic acid methyl ester was dissolved in 20mL of methanol). React for 8h. After completion of the reaction system was added to 10mL of water, stirred for 2h after suction filtration, the filter cake washed with copious amounts of water to pH 6-7, and then with hot n-heptane was washed twice 20mL, drained to give the product A1, drying in 10.8g . The yield was 70%, |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
83 %Chromat. | With gallium(III) triflate at 140℃; for 1h; | 1 Example 2. Preparation of 1,4-anhydroribitol from ribitol catalyzed by a) hafnium triflate and b) gallium triflate. General procedure: A general experimental protocol for the dehydration of pentitols to anhydropentitols is as follows: A 25 mL round bottomed flask equipped with a PTFE coated magnetic stir bar was charged with 10.00 g of a pentitol (65.7 mmol) and 0.1 mol% of hafnium triflate (51 mg) or gallium triflate (34 mg). A short path condenser affixed to a vacuum line was then attached to flask and while under vacuum (<1 torr), the mixture was heated to 140°C for 1 h in an oil bath. After this time, the vacuum was broken and contents cooled to room temperature. An aliquot was then removed and analyzed by GC. A general description for the protocol used to purify 1,4-anhydropentitol is as follows: To a 100 mL, four-neck round bottomed flask was charged 50 g of aforementioned anhydropentitol product mixture. The leftmost neck was affixed with a 30 cm Vigreux fractionating column, to the center neck an overhead stirrer with a Teflon blade, the rightmost neck a thermowell adapter threaded with a temperature probe, and the remaining frontal neck a ground glass adapter attached to a vacuum line. The flask was then enveloped in a spherical, soft-shell heating mantle and heated to 250-260°C (as indicated by the temp probe) under reduced pressure (≤ 1 torr). Approximately 30-35 g of distillate was collected for each dehydrated pentitol. GC analysis of each manifested a lone salient signal indicating a highly pure 1,4-anhydropentitol (sans corresponding minor 1,5-anhydropentitol signal). |
With silicotungstic acid hexacosahydrate at 115℃; for 5h; | 15 As a dehydration catalyst, using tungsten silicide 26 acid hydrate, was synthesized by dehydration reaction of the sorbitol isosorbide. Specific synthesis procedure is as follows. That is, reflux condenser, moisture determination receiver, 100 ml four neck flask fitted with Teflon coated thermocouple, sorbitol (99% chemical reagent [kishida[kishida]) D - 40mmol, tungstic acid hydrate (99% chemical reagent [kishida[kishida]) silicate 26 4mmol, tetrahydropyran (Tokyo chemical reagent 98%) 50 ml made of PFA and the stirring element is loaded. The, oil bath (oil bath temperature) using the reactor temperature controller 115 °C heated, while stirring the contents were stirred to a dehydration reaction. 5 after a lapse of time, the reactor is cooled, organic solvent phase was collected with a pipette. 50 ml (oil bath temperature) in addition to the tetrahydropyran-catalyst remaining in 85 °C 1 hours, the catalyst was extracted isosorbide included in phase. The organic solvent phase (99% pure chemical reagent wako) was added as an internal standard substance diphenyl ether, in the presence of pyridine in 20 min (gas chromatogram for pure drug wako) is heated by the 70 °C N - [torimechirushiriruimidazoru[torimechirushiriruimidazoru], analysis samples were prepared. Capillary gas chromatograph (0.25 μm [ajirentotekunoroji[ajirentotekunoroji], 0.250mm Φ × 60m) mounted DB-a 1 products were analyzed. The results are shown in table 1. As shown in table 1, with respect to the amount of sorbitol, after the dehydration reaction of the organic solvent phases from 46mol %, catalyst phase extracted from the organic solvent phase 20mol %, 66mol % isosorbide was obtained according. | |
In water at 249.84℃; Inert atmosphere; |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
90% | Sugar based amphiphiles were synthesized by conventional solution phase methodology as represented inScheme 1. 60 mL cyclohexane was added to a round bottomed flask followed by 15 mL of MeOH and kept under N2 atmosphere. Xylitol (4.2 g, 27.5 mmol) and p-TsOH (0.5 g, 2.7 mmol) was added to the solvent mixture and heated to 80C for 10 min. Then benzaldehyde (5.6 ml, 55 mmol) was added to the former solution and the whole mixture was refluxed at 80C for 2 hours. After the reaction, solvent was removed under reduced pressure on a rotary evaporator to obtain a white solid. The solid was washed with DCM followed by water and filtered. The product 1 was obtained as a white solid in 90% yield.1H NMR (500 MHz, CDC13, rt): delta =7.60-7.58 (dd,4H), 7.54-7.52 (t, 2H), 7.41-7.34 (m, 4H), 5.66 (s, 1H), 5.58 (s, 1H), 4.41-4.39 (dd, 1H), 4.16-4.14 (dd, 1H), 4.09-3.97 (m, 3H), 3.86-3.84 (dd, 2H). |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
64% | Compound 2 was also synthesized following the reaction procedure as that of previous reaction but using acetophenone (27.5 mmol) instead of benzaldehyde. The reaction was performed for 12 hours in this case. The mixturethus obtained after reaction was subjected to washing by DCM and water and the product was isolated as a white solid after drying in 64% yield.?H NMR (500 MHz, CDC13, rt): oe =7.97-7.95 (d, 4H), 7.58-7.55 (t, 2H), 7.48-7.46 (t, 4H), 4.42-4.39 (dd, 1H), 4.23-4.21 (dd, 1H), 4.08-3.87 (m, 3H), 3.55-3.53 (dd, 2H), 1.68 (s, 6H). |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
62% | Compound 3 was also synthesized following the reaction procedure as that of compound 1 but using phenyl ethyl ketone (27.5 mmol) instead of benzaldehyde. The reaction wasperformed for 24 hours in this case. The mixturethus obtained after reaction was subjected to washing by DCM and water where the product was isolated as a white solid after drying in 62% yield.?H NMR (500 MHz, CDC13, rt): oe =7.97-7.95 (d, 4H), 7.57-7.53 (t, 2H), 7.47-7.43 (t, 4H), 4.43-4.41(dd, 1H), 4.20-4. 17 (dd, 1H), 4.05-3.80 (m, 3H), 3.53-3.50 (dd, 2H), 3.03-2.98 (q, 4H),1.24-1.21 (t, 6H). |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With 5% Pd/C; hydrogen; In cyclohexane; water; at 149.84℃; under 22502.3 Torr; for 4h;Autoclave; | General procedure: The conversion of xylose was performed in a 100 ml stirred autoclave.In a typical experiment, 200 mg reagent, 200 mg acid catalyst,50 mg hydrogenation catalyst, and 32 g solvent were loaded into thevessel, respectively. The aqueous phase and organic solvent were usedin the mass ratio of 1:1. After sealed and pressurized with H2 to 3.0Mpa, the reactor was heated to 423 K and stirred for 4 h, then the autoclavewas cooled in an ice-water bath. Products were filtered througha membrane filter (0.2 mum pore size) prior to analysis. Xylose and xylitolwere analyzed on an Agilent 1200 Series HPLC equipped with arefractive index detector with a Bio-Rad HPX-87H column using anaqueous solution of H2SO4 at 5 mmol/L as mobile phase (0.7 ml/min).1,2-PeD and other products (1,4-PeD, CPO, CPL, FF, 1-H-2-P, THFA,GVL, n-pentyl alcohol, and sec-pentanol) were quantified by FID-GC(Shimadzu 2014C with a column of DB-FFAP, 30 m). The conversion ofxylose, the selectivity and yield of products were determined from Eqs.(1), (2), and (3), respectively. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With 5% Pd/C; hydrogen; In cyclohexane; water; at 149.84℃; under 22502.3 Torr; for 4h;Autoclave; | General procedure: The conversion of xylose was performed in a 100 ml stirred autoclave.In a typical experiment, 200 mg reagent, 200 mg acid catalyst,50 mg hydrogenation catalyst, and 32 g solvent were loaded into thevessel, respectively. The aqueous phase and organic solvent were usedin the mass ratio of 1:1. After sealed and pressurized with H2 to 3.0Mpa, the reactor was heated to 423 K and stirred for 4 h, then the autoclavewas cooled in an ice-water bath. Products were filtered througha membrane filter (0.2 mum pore size) prior to analysis. Xylose and xylitolwere analyzed on an Agilent 1200 Series HPLC equipped with arefractive index detector with a Bio-Rad HPX-87H column using anaqueous solution of H2SO4 at 5 mmol/L as mobile phase (0.7 ml/min).1,2-PeD and other products (1,4-PeD, CPO, CPL, FF, 1-H-2-P, THFA,GVL, n-pentyl alcohol, and sec-pentanol) were quantified by FID-GC(Shimadzu 2014C with a column of DB-FFAP, 30 m). The conversion ofxylose, the selectivity and yield of products were determined from Eqs.(1), (2), and (3), respectively. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With 5% Pd/C; hydrogen; In cyclohexane; water; at 149.84℃; under 22502.3 Torr; for 4h;Autoclave; | General procedure: The conversion of xylose was performed in a 100 ml stirred autoclave.In a typical experiment, 200 mg reagent, 200 mg acid catalyst,50 mg hydrogenation catalyst, and 32 g solvent were loaded into thevessel, respectively. The aqueous phase and organic solvent were usedin the mass ratio of 1:1. After sealed and pressurized with H2 to 3.0Mpa, the reactor was heated to 423 K and stirred for 4 h, then the autoclavewas cooled in an ice-water bath. Products were filtered througha membrane filter (0.2 mum pore size) prior to analysis. Xylose and xylitolwere analyzed on an Agilent 1200 Series HPLC equipped with arefractive index detector with a Bio-Rad HPX-87H column using anaqueous solution of H2SO4 at 5 mmol/L as mobile phase (0.7 ml/min).1,2-PeD and other products (1,4-PeD, CPO, CPL, FF, 1-H-2-P, THFA,GVL, n-pentyl alcohol, and sec-pentanol) were quantified by FID-GC(Shimadzu 2014C with a column of DB-FFAP, 30 m). The conversion ofxylose, the selectivity and yield of products were determined from Eqs.(1), (2), and (3), respectively. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With niobium(V) oxide; 5% Pd/C; hydrogen; In cyclohexane; water; at 149.84℃; under 22502.3 Torr; for 4h;Autoclave; | General procedure: The conversion of xylose was performed in a 100 ml stirred autoclave.In a typical experiment, 200 mg reagent, 200 mg acid catalyst,50 mg hydrogenation catalyst, and 32 g solvent were loaded into thevessel, respectively. The aqueous phase and organic solvent were usedin the mass ratio of 1:1. After sealed and pressurized with H2 to 3.0Mpa, the reactor was heated to 423 K and stirred for 4 h, then the autoclavewas cooled in an ice-water bath. Products were filtered througha membrane filter (0.2 mum pore size) prior to analysis. Xylose and xylitolwere analyzed on an Agilent 1200 Series HPLC equipped with arefractive index detector with a Bio-Rad HPX-87H column using anaqueous solution of H2SO4 at 5 mmol/L as mobile phase (0.7 ml/min).1,2-PeD and other products (1,4-PeD, CPO, CPL, FF, 1-H-2-P, THFA,GVL, n-pentyl alcohol, and sec-pentanol) were quantified by FID-GC(Shimadzu 2014C with a column of DB-FFAP, 30 m). The conversion ofxylose, the selectivity and yield of products were determined from Eqs.(1), (2), and (3), respectively. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With niobium(V) oxide; 5% Pd/C; hydrogen; In cyclohexane; water; at 149.84℃; under 22502.3 Torr; for 4h;Autoclave; | General procedure: The conversion of xylose was performed in a 100 ml stirred autoclave.In a typical experiment, 200 mg reagent, 200 mg acid catalyst,50 mg hydrogenation catalyst, and 32 g solvent were loaded into thevessel, respectively. The aqueous phase and organic solvent were usedin the mass ratio of 1:1. After sealed and pressurized with H2 to 3.0Mpa, the reactor was heated to 423 K and stirred for 4 h, then the autoclavewas cooled in an ice-water bath. Products were filtered througha membrane filter (0.2 mum pore size) prior to analysis. Xylose and xylitolwere analyzed on an Agilent 1200 Series HPLC equipped with arefractive index detector with a Bio-Rad HPX-87H column using anaqueous solution of H2SO4 at 5 mmol/L as mobile phase (0.7 ml/min).1,2-PeD and other products (1,4-PeD, CPO, CPL, FF, 1-H-2-P, THFA,GVL, n-pentyl alcohol, and sec-pentanol) were quantified by FID-GC(Shimadzu 2014C with a column of DB-FFAP, 30 m). The conversion ofxylose, the selectivity and yield of products were determined from Eqs.(1), (2), and (3), respectively. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With enzyme phospholipase D In diethyl ether at 22 - 37℃; for 18h; Enzymatic reaction; | 1 Transphosphatidylation Reaction: General procedure: A transphosphatidylation reaction with the enzyme phospholipase D (PLD) was utilized to synthesize analogs of POPG as previously described by S. F. Yang et al ("Transphosphatidylation by phospholipase D.," J. Biol. Chem., vol. 242, no. 3, pp. 477-84, Feb. 1967). PLD catalyzes the hydrolytic cleavage of terminal phosphate ester bonds of glycerophospholipids with a choline head group but in the presence of an excess of primary alcohol, catalyzes a transphosphatidylase reaction, which exchanges the choline head group for that of the primary alcohol. This method was used to synthesize analogs that contain a xylitol polar head group that differ in their hydrophobic chains. (0157) Aliquots of 5-10 mg of phosphatidylcholine (PC) species in chloroform were dried under a stream of nitrogen gas. Diethyl ether was added to the dried PC species, and once again dried using nitrogen gas to eliminate all of the chloroform. Dried PC species were resuspended in 3.1 mL of diethyl ether. Xylitol at 40%-50% (w/v) was dissolved in a pH 5.5 sodium acetate buffer that contained 120 mM calcium chloride in a final volume of 500 ^L. This aqueous solution was then added to the ether phase of the reaction followed by the addition of PLD at a final concentration of 120 units/mL. The reaction mixture was vortexed 18-24 hours at temperatures ranging from 22°C to 42.5°C. Reactions were stopped by the addition of 50 [iL 0.5 M EDTA. Ether was evaporated under a stream of nitrogen and the lipids were extracted using the Bligh-Dyer method ("A rapid method of total lipid extraction and purification.," Can. J. Biochem. Physiol., vol. 37, no. 8, pp. 911-7, Aug. 1959). Reaction progress was assessed using thin layer chromatography and visualized using 0.1% aqueous (0158) ANSA, followed by exposure to UV light. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With enzyme phospholipase D In diethyl ether at 42.5℃; for 24h; Enzymatic reaction; | 1 Transphosphatidylation Reaction: General procedure: A transphosphatidylation reaction with the enzyme phospholipase D (PLD) was utilized to synthesize analogs of POPG as previously described by S. F. Yang et al ("Transphosphatidylation by phospholipase D.," J. Biol. Chem., vol. 242, no. 3, pp. 477-84, Feb. 1967). PLD catalyzes the hydrolytic cleavage of terminal phosphate ester bonds of glycerophospholipids with a choline head group but in the presence of an excess of primary alcohol, catalyzes a transphosphatidylase reaction, which exchanges the choline head group for that of the primary alcohol. This method was used to synthesize analogs that contain a xylitol polar head group that differ in their hydrophobic chains. (0157) Aliquots of 5-10 mg of phosphatidylcholine (PC) species in chloroform were dried under a stream of nitrogen gas. Diethyl ether was added to the dried PC species, and once again dried using nitrogen gas to eliminate all of the chloroform. Dried PC species were resuspended in 3.1 mL of diethyl ether. Xylitol at 40%-50% (w/v) was dissolved in a pH 5.5 sodium acetate buffer that contained 120 mM calcium chloride in a final volume of 500 ^L. This aqueous solution was then added to the ether phase of the reaction followed by the addition of PLD at a final concentration of 120 units/mL. The reaction mixture was vortexed 18-24 hours at temperatures ranging from 22°C to 42.5°C. Reactions were stopped by the addition of 50 [iL 0.5 M EDTA. Ether was evaporated under a stream of nitrogen and the lipids were extracted using the Bligh-Dyer method ("A rapid method of total lipid extraction and purification.," Can. J. Biochem. Physiol., vol. 37, no. 8, pp. 911-7, Aug. 1959). Reaction progress was assessed using thin layer chromatography and visualized using 0.1% aqueous (0158) ANSA, followed by exposure to UV light. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
88% | With sodium acetate; at 135 - 145℃; for 3h; | Take 20g of xylitol, 75g of diphenyl carbonate, 1g of sodium acetate, and heat up to 135-145 C for 3h; vacuum distillationNo liquid is produced, filtered by cooling, and 23.5 g of intermediate is obtained, the yield is 88.0%, and the purity is 99.8%. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With hydrogen; In water; at 180℃; under 37503.8 Torr;Autoclave; | Hydrolytic hydrogenation of alginic acid was carried out in an autoclave(100 mL, Parr Instrument Company). Alginic acid (0.3 g), distilledwater (30 mL), and a catalyst (0.1 g) were charged into the autoclave.The vessel was heated to 150 C or 180 C under 50 bar of H2after purging with 50 bar of H2 three times to remove air inside. After adesired reaction time, the reactor was quickly quenched in an ice-coldbath to avoid side reactions. The liquid mixture inside the vessel wasagitated with an impeller at 1000 rpm during heating of the reactor andreaction at the designated temperature. Recyclability experiment wasperformed using a multi-batch process according to a previously reportedmethod to compensate weight loss of the catalyst during a catalystrecovery step [16]. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With hydrogen; In water; at 180℃; under 37503.8 Torr;Autoclave; | Hydrolytic hydrogenation of alginic acid was carried out in an autoclave(100 mL, Parr Instrument Company). Alginic acid (0.3 g), distilledwater (30 mL), and a catalyst (0.1 g) were charged into the autoclave.The vessel was heated to 150 C or 180 C under 50 bar of H2after purging with 50 bar of H2 three times to remove air inside. After adesired reaction time, the reactor was quickly quenched in an ice-coldbath to avoid side reactions. The liquid mixture inside the vessel wasagitated with an impeller at 1000 rpm during heating of the reactor andreaction at the designated temperature. Recyclability experiment wasperformed using a multi-batch process according to a previously reportedmethod to compensate weight loss of the catalyst during a catalystrecovery step [16]. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
92% | With barium hydroxide octahydrate; In methanol; at 140℃; for 12h;Inert atmosphere; Sealed tube; | Under the protection of nitrogen atmosphere, into a 15mL thick-walled pressure-resistant bottle, a nitrogen heterocyclic carbene iridium solid molecular catalyst 2b (0.003g, 0.2mol%), barium hydroxide octahydrate (1.89g, 6mmol), and xylitol (0.45g, 3mmol) were sequentially added, methanol (2 mL). After the thick-walled pressure-resistant bottle was sealed, it was placed in an oil bath and heated to 140 C for 12 hours. After the reaction was completed, it was cooled to room temperature, and the reaction solution was diluted with 10 mL of deionized water. And transfer the diluted reaction solution to a centrifuge tube, centrifuge at 10,000 r/min for 10 minutes. Take the supernatant and dilute with 1M H2SO4. The diluted liquid was subjected to high performance liquid chromatography to measure xylitol conversion and lactic acid yield. The conversion of xylitol was 99%, and the yield of lactic acid was 92%. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With hydrogen In 1,4-dioxane at 160℃; for 4h; Sealed tube; | 1 In an example reaction, 2 g xylitol was added into a batch reactor along with 0.60 g of 4 wt % catalyst. Dioxane was added to the reactor along with a stir bar, and the reactor sealed and checked for leaks using an inert gas. The reactor was brought to a reaction temperature of 160° C. and charged with a gas containing substantially pure H2 to a pressure of 10 bat The reaction was conducted over a period of 4 hours, and the concentration of 1,2-dideoxypentitol; 1,2,5-pentanetriol; 1-pentanol; and 3-pentanol was monitored over the course of reaction. Afier 4 hours, the conversion of xylitol was calculated as 5 9.4%. |
Tags: 87-99-0 synthesis path| 87-99-0 SDS| 87-99-0 COA| 87-99-0 purity| 87-99-0 application| 87-99-0 NMR| 87-99-0 COA| 87-99-0 structure
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